Shaped abrasive particles and method of forming same

ABSTRACT

An abrasive particle including a shaped abrasive particle including a body having a plurality of abrasive particles bonded to at least one surface of the body of the shaped abrasive particle.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a Continuation of U.S. patent application Ser. No.14/757,688, entitled “SHAPED ABRASIVE PARTICLES AND METHOD OF FORMINGSAME,” by Frederic Josseaux and David F. Louapre, filed Dec. 23, 2015,which is a Continuation-in-Part to U.S. patent application Ser. No.14/581,220, entitled “COMPOSITE SHAPED ABRASIVE PARTICLES AND METHOD OFFORMING SAME,” by Frederic Josseaux, filed Dec. 23, 2014, now U.S. Pat.No. 9,707,529, and claims priority to U.S. Provisional Application No.62/141,181 entitled “SHAPED ABRASIVE PARTICLES AND METHOD OF FORMINGSAME,” by Frederic Josseaux and David F. Louapre, filed Mar. 31, 2015,which are assigned to the current assignee hereof and incorporatedherein by reference in their entireties.

BACKGROUND Field of the Disclosure

The following is directed to shaped abrasive particles, and moreparticularly, to composite shaped abrasive particles having certainfeatures and methods of forming such composite shaped abrasiveparticles.

Description of the Related Art

Abrasive articles incorporating abrasive particles are useful forvarious material removal operations including grinding, finishing,polishing, and the like. Depending upon the type of abrasive material,such abrasive particles can be useful in shaping or grinding variousmaterials in the manufacturing of goods. Certain types of abrasiveparticles have been formulated to date that have particular geometries,such as triangular shaped abrasive particles and abrasive articlesincorporating such objects. See, for example, U.S. Pat. Nos. 5,201,916;5,366,523; and 5,984,988.

Previously, three basic technologies that have been employed to produceabrasive particles having a specified shape, which are fusion,sintering, and chemical ceramic. In the fusion process, abrasiveparticles can be shaped by a chill roll, the face of which may or maynot be engraved, a mold into which molten material is poured, or a heatsink material immersed in an aluminum oxide melt. See, for example, U.S.Pat. No. 3,377,660. In sintering processes, abrasive particles can beformed from refractory powders having a particle size of up to 10micrometers in diameter. Binders can be added to the powders along witha lubricant and a suitable solvent to form a mixture that can be shapedinto platelets or rods of various lengths and diameters. See, forexample, U.S. Pat. No. 3,079,242. Chemical ceramic technology involvesconverting a colloidal dispersion or hydrosol (sometimes called a sol)to a gel or any other physical state that restrains the mobility of thecomponents, drying, and firing to obtain a ceramic material. See, forexample, U.S. Pat. Nos. 4,744,802 and 4,848,041. Other relevantdisclosures on shaped abrasive particles and associated methods offorming and abrasive articles incorporating such particles are availableat: http://www.abel-ip.com/publications/.

The industry continues to demand improved abrasive materials andabrasive articles.

SUMMARY

According to a first aspect, a method of forming an abrasive particleincludes forming a mixture and attaching a plurality of abrasiveparticles to at least one surface of the mixture and forming a shapedabrasive particle having a body and the plurality of abrasive particlesbonded to at least one surface of the body.

In yet another aspect, an abrasive article includes a bond material anda first collection of abrasive particles coupled to the bond material,wherein each particle in the first collection comprises a shapedabrasive particle comprising a body and a plurality of abrasiveparticles bonded to at least one surface of the body of the shapedabrasive particle.

In another aspect, an abrasive particle includes a shaped abrasiveparticle comprising a body; and a plurality of abrasive particles bondedto at least one surface of the body of the shaped abrasive particle.

BRIEF DESCRIPTION OF THE FIGURES

The present disclosure may be better understood, and its numerousfeatures and advantages made apparent to those skilled in the art byreferencing the accompanying drawings.

FIG. 1A includes a portion of a system for forming shaped abrasiveparticles in accordance with an embodiment.

FIG. 1B includes a portion of the system of FIG. 1 according to anembodiment.

FIG. 2 includes a portion of an alternative system for forming shapedabrasive particles in accordance with an embodiment.

FIG. 3 includes an image of an abrasive particle according to anembodiment.

FIG. 4 includes a three-dimensional image of an abrasive particleaccording to an embodiment.

FIG. 5 includes a perspective view illustration of a shaped abrasiveparticle that may be form the base of an abrasive particle in accordancewith an embodiment.

FIG. 6A includes a perspective view illustration of a shaped abrasiveparticle that may be used in accordance with an abrasive particle of anembodiment.

FIG. 6B includes a perspective view illustration of a non-shapedabrasive particle that may be used in accordance with an abrasiveparticle of an embodiment.

FIGS. 7A-7D include illustrations of shaped abrasive particles that maybe used in accordance with an abrasive particle of an embodiment.

FIG. 8 includes a cross-sectional image of a shaped abrasive particleaccording to an embodiment.

FIG. 9 includes a top-down view of a shaped abrasive particle accordingto an embodiment.

FIG. 10 includes a cross-sectional illustration of a shaped abrasiveparticle according to an embodiment.

FIG. 11 includes cross-sectional image of a shaped abrasive particleaccording to an embodiment.

FIG. 12A includes a cross-sectional illustration of a coated abrasivearticle according to an embodiment.

FIG. 12B includes a perspective view illustration of a coated abrasivearticle including an abrasive particle according to an embodiment.

FIG. 13A includes an illustration of a bonded abrasive article accordingto an embodiment.

FIG. 13B includes an illustration of a bonded abrasive article includingan abrasive particle according to an embodiment.

FIG. 14 includes an image of a conventional shaped abrasive particle.

FIG. 15 includes images of an abrasive particle according to anembodiment.

FIG. 16 includes images of an abrasive particle according to anembodiment.

FIG. 17 includes a plot of force per total area removed for aconventional sample and a representative sample.

FIG. 18 includes a plot of specific grinding energy versus cumulativematerial removed for three samples of coated abrasive articles.

FIG. 19 includes a plot of specific grinding energy versus cumulativematerial removed from the workpiece.

FIGS. 20A-20E include images of representative abrasive particlesaccording to embodiments herein.

FIG. 21 includes a plot of force per total area removed from theworkpiece according to the single grit grinding test for a conventionalsamples and representative samples according to embodiments.

FIG. 22 includes a plot of relative performance (% cut) for aconventional sample and representative samples according to embodimentsherein.

DETAILED DESCRIPTION

The following is directed to methods of forming shaped abrasiveparticles, and more particularly composite shaped abrasive particlesincluding shaped abrasive particles and a plurality of abrasiveparticles overlying at least one surface of the body of the shapedabrasive particle. The abrasive particles of the embodiments herein maybe used in various abrasive articles, including for example bondedabrasive articles, coated abrasive articles, and the like.Alternatively, the shaped abrasive particle fractions of the embodimentsherein may be utilized in free abrasive technologies, including forexample grinding and/or polishing slurries.

The abrasive particles of the embodiments herein may be obtained throughvarious processing methods, including but not limited to, printing,molding, pressing, stamping, casting, extruding, cutting, fracturing,heating, cooling, crystallizing, rolling, embossing, depositing,etching, scoring, drying, and a combination thereof. Particular methodsof forming the shaped abrasive particles can include the formation of amixture, such as a sol-gel, that can be shaped in an opening of aproduction tooling (e.g., a screen or mold), and formed into a precursorshaped abrasive particle. Screen printing methods of forming shapedabrasive particles are generally described in U.S. Pat. No. 8,753,558. Asuitable method of forming shaped abrasive particles according to aconventional molding process is described in U.S. Pat. Nos. 5,201,916.

According to one particular embodiment, the process of forming theshaped abrasive particles can be a screen printing process. FIG. 1Aincludes an illustration of a system 150 for forming composite shapedabrasive particles in accordance with one, non-limiting embodiment.

The process of forming composite shaped abrasive particles can beinitiated by forming a mixture 101 including a ceramic material and aliquid. In particular, the mixture 101 can be a gel formed of a ceramicpowder material and a liquid, wherein the gel can be characterized as ashape-stable material having the ability to substantially hold a givenshape even in the green (i.e., unfired) state. In accordance with anembodiment, the gel can be formed of the ceramic powder material as anintegrated network of discrete particles.

The mixture 101 may contain a certain content of solid material, liquidmaterial, and additives such that it has suitable rheologicalcharacteristics for use with the process detailed herein. That is, incertain instances, the mixture can have a certain viscosity, and moreparticularly, suitable rheological characteristics that form ashape-stable phase of material that can be formed through the process asnoted herein. A dimensionally stable phase of material is a materialthat can be formed to have a particular shape and substantially maintainthe shape for at least a portion of the processing subsequent toforming. In certain instances, the shape may be retained throughoutsubsequent processing, such that the shape initially provided in theforming process is present in the finally-formed object.

The mixture 101 can be formed to have a particular content of solidmaterial, such as the ceramic powder material. For example, in oneembodiment, the mixture 101 can have a solids content of at least about25 wt %, such as at least about 35 wt %, or even at least about 38 wt %for the total weight of the mixture 101. Still, in at least onenon-limiting embodiment, the solids content of the mixture 101 can benot greater than about 75 wt %, such as not greater than about 70 wt %,not greater than about 65 wt %, not greater than about 55 wt %, notgreater than about 45 wt %, or not greater than about 42 wt %. It willbe appreciated that the content of the solid material in the mixture 101can be within a range between any of the minimum and maximum percentagesnoted above.

According to one embodiment, the ceramic powder material can include anoxide, a nitride, a carbide, a boride, an oxycarbide, an oxynitride, anda combination thereof. In particular instances, the ceramic material caninclude alumina. More specifically, the ceramic material may include aboehmite material, which may be a precursor of alpha alumina. The term“boehmite” is generally used herein to denote alumina hydrates includingmineral boehmite, typically being Al2O3.H2O and having a water contenton the order of 15%, as well as pseudoboehmite, having a water contenthigher than 15%, such as 20-38% by weight. It is noted that boehmite(including pseudoboehmite) has a particular and identifiable crystalstructure, and therefore a unique X-ray diffraction pattern. As such,boehmite is distinguished from other aluminous materials including otherhydrated aluminas such as ATH (aluminum trihydroxide), a commonprecursor material used herein for the fabrication of boehmiteparticulate materials.

Furthermore, the mixture 101 can be formed to have a particular contentof liquid material. Some suitable liquids may include water. In moreparticular instances, the mixture 101 can have a liquid content of atleast about 25 wt % for the total weight of the mixture 101. In otherinstances, the amount of liquid within the mixture 101 can be greater,such as at least about 35 wt %, at least about 45 wt %, at least about50 wt %, or even at least about 58 wt %. Still, in at least onenon-limiting embodiment, the liquid content of the mixture can be notgreater than about 75 wt %, such as not greater than about 70 wt %, notgreater than about 65 wt %, not greater than about 62 wt %, or even notgreater than about 60 wt %. It will be appreciated that the content ofthe liquid in the mixture 101 can be within a range between any of theminimum and maximum percentages noted above.

Furthermore, to facilitate processing and forming shaped abrasiveparticles according to embodiments herein, the mixture 101 can have aparticular storage modulus. For example, the mixture 101 can have astorage modulus of at least about 1×10⁴ Pa, such as at least about 4×10⁴Pa, or even at least about 5×10⁴ Pa. However, in at least onenon-limiting embodiment, the mixture 101 may have a storage modulus ofnot greater than about 1×10⁷ Pa, such as not greater than about 2×10⁶Pa. It will be appreciated that the storage modulus of the mixture 101can be within a range between any of the minimum and maximum valuesnoted above.

The storage modulus can be measured via a parallel plate system usingARES or AR-G2 rotational rheometers, with Peltier plate temperaturecontrol systems. For testing, the mixture 101 can be extruded within agap between two plates that are set to be approximately 8 mm apart fromeach other. After extruding the gel into the gap, the distance betweenthe two plates defining the gap is reduced to 2 mm until the mixture 101completely fills the gap between the plates. After wiping away excessmixture, the gap is decreased by 0.1 mm and the test is initiated. Thetest is an oscillation strain sweep test conducted with instrumentsettings of a strain range between 0.01% to 100%, at 6.28 rad/s (1 Hz),using 25-mm parallel plate and recording 10 points per decade. Within 1hour after the test completes, the gap is lowered again by 0.1 mm andthe test is repeated. The test can be repeated at least 6 times. Thefirst test may differ from the second and third tests. Only the resultsfrom the second and third tests for each specimen should be reported.

Furthermore, to facilitate processing and forming shaped abrasiveparticles according to embodiments herein, the mixture 101 can have aparticular viscosity. For example, the mixture 101 can have a viscosityof at least about 4×10³ Pa s, at least about 5×10³ Pa s, at least about6×10³ Pa s, at least about 8×10³ Pa s, at least about 10×10³ Pa s, atleast about 20×10³ Pa s, at least about 30×10³ Pa s, at least about40×10³ Pa s, at least about 50×10³ Pa s, at least about 60×10³ Pa s, orat least about 65×10³ Pa s. In one non-limiting embodiment, the mixture101 may have a viscosity of not greater than about 100×10³ Pa s, such asnot greater than about 95×10³ Pa s, not greater than about 90×10³ Pa s,or even not greater than about 85×10³ Pa s. It will be appreciated thatthe viscosity of the mixture 101 can be within a range between any ofthe minimum and maximum values noted above. The viscosity can bemeasured in the same manner as the storage modulus as described above.

Moreover, the mixture 101 can be formed to have a particular content oforganic materials including, for example, organic additives that can bedistinct from the liquid to facilitate processing and formation ofshaped abrasive particles according to the embodiments herein. Somesuitable organic additives can include stabilizers, binders such asfructose, sucrose, lactose, glucose, UV curable resins, and the like.

Notably, the embodiments herein may utilize a mixture 101 that can bedistinct from slurries used in conventional forming operations. Forexample, the content of organic materials within the mixture 101 and, inparticular, any of the organic additives noted above, may be a minoramount as compared to other components within the mixture 101. In atleast one embodiment, the mixture 101 can be formed to have not greaterthan about 30 wt % organic material for the total weight of the mixture101. In other instances, the amount of organic materials may be less,such as not greater than about 15 wt %, not greater than about 10 wt %,or even not greater than about 5 wt %. Still, in at least onenon-limiting embodiment, the amount of organic materials within themixture 101 can be at least about 0.01 wt %, such as at least about 0.5wt % for the total weight of the mixture 101. It will be appreciatedthat the amount of organic materials in the mixture 101 can be within arange between any of the minimum and maximum values noted above.

Moreover, the mixture 101 can be formed to have a particular content ofacid or base, distinct from the liquid content, to facilitate processingand formation of shaped abrasive particles according to the embodimentsherein. Some suitable acids or bases can include nitric acid, sulfuricacid, citric acid, chloric acid, tartaric acid, phosphoric acid,ammonium nitrate, and ammonium citrate. According to one particularembodiment in which a nitric acid additive is used, the mixture 101 canhave a pH of less than about 5, and more particularly, can have a pHwithin a range between about 2 and about 4.

The system 150 of FIG. 1A, can include a die 103. As illustrated, themixture 101 can be provided within the interior of the die 103 andconfigured to be extruded through a die opening 105 positioned at oneend of the die 103. As further illustrated, extruding can includeapplying a force 180 (such as a pressure) on the mixture 101 tofacilitate extruding the mixture 101 through the die opening 105. Duringextrusion within an application zone 183, a production tool orproduction tool 151 can be in direct contact with a portion of a belt109. The screen printing process can include extruding the mixture 101from the die 103 through the die opening 105 in a direction 191. Inparticular, the screen printing process may utilize the production tool151 such that, upon extruding the mixture 101 through the die opening105, the mixture 101 can be forced into an opening 152 in the productiontool 151.

In accordance with an embodiment, a particular pressure may be utilizedduring extrusion. For example, the pressure can be at least about 10kPa, such as at least about 500 kPa. Still, in at least one non-limitingembodiment, the pressure utilized during extrusion can be not greaterthan about 4 MPa. It will be appreciated that the pressure used toextrude the mixture 101 can be within a range between any of the minimumand maximum values noted above. In particular instances, the consistencyof the pressure delivered by a piston 199 may facilitate improvedprocessing and formation of shaped abrasive particles. Notably,controlled delivery of consistent pressure across the mixture 101 andacross the width of the die 103 can facilitate improved processingcontrol and improved dimensional characteristics of the shaped abrasiveparticles.

Referring briefly to FIG. 1B, a portion of the production tool (e.g.,screen) 151 is illustrated. As shown, the production tool 151 caninclude the opening 152, and more particularly, a plurality of openings152 extending through the volume of the production tool 151. Inaccordance with an embodiment, the openings 152 can have atwo-dimensional shape as viewed in a plane defined by the length (1) andwidth (w) of the screen. The two-dimensional shape can include variousshapes such as, for example, polygons, ellipsoids, numerals, Greekalphabet letters, Latin alphabet letters, Russian alphabet characters,complex shapes including a combination of polygonal shapes, and acombination thereof. In particular instances, the openings 152 may havetwo-dimensional polygonal shapes such as a triangle, a rectangle, aquadrilateral, a pentagon, a hexagon, a heptagon, an octagon, a nonagon,a decagon, and a combination thereof.

As further illustrated, the production tool 151 can have openings 152that are oriented in a particular manner relative to each other. Asillustrated and in accordance with one embodiment, each of the openings152 can have substantially the same orientation relative to each other,and substantially the same orientation relative to the surface of theproduction tool 151. For example, each of the openings 152 can have afirst edge 154 defining a first plane 155 for a first row 156 of theopenings 152 extending laterally across a lateral axis 158 of theproduction tool 151. The first plane 155 can extend in a directionsubstantially orthogonal to a longitudinal axis 157 of the productiontool 151. However, it will be appreciated, that in other instances, theopenings 152 need not necessarily have the same orientation relative toeach other.

Moreover, the first row 156 of openings 152 can be oriented relative toa direction of translation to facilitate particular processing andcontrolled formation of shaped abrasive particles. For example, theopenings 152 can be arranged on the production tool 151 such that thefirst plane 155 of the first row 156 defines an angle relative to thedirection of translation 171. As illustrated, the first plane 155 candefine an angle that is substantially orthogonal to the direction oftranslation 171. Still, it will be appreciated that in one embodiment,the openings 152 can be arranged on the production tool 151 such thatthe first plane 155 of the first row 156 defines a different angle withrespect to the direction of translation, including for example, an acuteangle or an obtuse angle. Still, it will be appreciated that theopenings 152 may not necessarily be arranged in rows. The openings 152may be arranged in various particular ordered distributions with respectto each other on the production tool 151, such as in the form of atwo-dimensional pattern. Alternatively, the openings may be disposed ina random manner on the production tool 151.

Referring again to FIG. 1A, after forcing the mixture 101 through thedie opening 105 and a portion of the mixture 101 through the openings152 in the production tool 151, one or more precursor shaped abrasiveparticles 123 may be printed on the belt 109 disposed under theproduction tool 151. According to a particular embodiment, the precursorshaped abrasive particles 123 can have a shape generally dictated by theshape of the openings 152 and the forming process. Notably, the mixture101 can be forced through the production tool 151 in rapid fashion, suchthat the average residence time of the mixture 101 within the openings152 can be less than about 2 minutes, less than about 1 minute, lessthan about 40 seconds, or even less than about 20 seconds. In particularnon-limiting embodiments, the mixture 101 may be substantially unalteredduring printing as it travels through the screen openings 152, thusexperiencing no change in the amount of components from the originalmixture, and may experience no appreciable drying in the openings 152 ofthe production tool 151. Still, in other instances, the mixture 101 mayundergo some drying in the openings 152, which may facilitate release ofthe mixture 101 from the openings 152 and may further facilitateformation of certain shape features of the shaped abrasive particles.

Additionally, the system 151 can include a bottom stage 198 within theapplication zone 183. During the process of forming shaped abrasiveparticles, the belt 109 can travel over the bottom stage 198, which canoffer a suitable substrate for forming the mixture 101.

During operation of the system 150, the production tool 151 can betranslated in a direction 153 while the belt 109 can be translated in adirection 110 substantially similar to the direction 153, at leastwithin the application zone 183, to facilitate a continuous printingoperation. As such, the precursor shaped abrasive particles 123 may beprinted onto the belt 109 and translated along the belt 109 to undergofurther processing. It will be appreciated that such further processingcan include processes described in the embodiments herein, including forexample, shaping, application of other materials (e.g., plurality ofabrasive particles), drying, sintering, and the like.

In some embodiments, the belt 109 and/or the production tool 151 can betranslated while extruding the mixture 101 through the die opening 105.As illustrated in the system 100, the mixture 101 may be extruded in adirection 191. The direction of translation 110 of the belt 109 and/orthe production tool 151 can be angled relative to the direction ofextrusion 191 of the mixture 101. While the angle between the directionof translation 110 and the direction of extrusion 191 is illustrated assubstantially orthogonal in the system 100, other angles arecontemplated, including for example, an acute angle or an obtuse angle.

The belt 109 and/or the production tool 151 may be translated at aparticular rate to facilitate processing. For example, the belt 109and/or the production tool 151 may be translated at a rate of at leastabout 3 cm/s. In other embodiments, the rate of translation of the belt109 and/or the production tool 151 may be greater, such as at leastabout 4 cm/s, at least about 6 cm/s, at least about 8 cm/s, or even atleast about 10 cm/s. Still, in at least one non-limiting embodiment, thebelt 109 and/or the production tool 151 may be translated in a direction110 at a rate of not greater than about 5 m/s, not greater than about 1m/s, or even not greater than about 0.5 m/s. It will be appreciated thatthe belt 109 and/or the production tool 151 may be translated at a ratewithin a range between any of the minimum and maximum values notedabove, and moreover, may be translated at substantially the same raterelative to each other. Furthermore, for certain processes according toembodiments herein, the rate of translation of the belt 109 as comparedto the rate of extrusion of the mixture 101 in the direction 191 may becontrolled to facilitate proper processing.

After the mixture 101 is extruded through the die opening 105, themixture 101 may be translated along the belt 109 under a knife edge 107attached to a surface of the die 103. The knife edge 107 may define aregion at the front of the die 103 that facilitates displacement of themixture 101 into the openings 152 of the production tool 151.

Certain processing parameters may be controlled to facilitate formationof particular features of the precursor shaped abrasive particles 123and the finally-formed shaped abrasive particles described herein. Someexemplary process parameters that can be controlled include a releasedistance 197, a viscosity of the mixture, a storage modulus of themixture, mechanical properties of the bottom stage, geometric ordimensional characteristics of the bottom stage, thickness of theproduction tool, rigidity of the production tool, a solid content of themixture, a carrier content of the mixture, a release angle, atranslation speed, a temperature, a content of release agent, a pressureexerted on the mixture, a speed of the belt, a drying rate, a dryingtime, a drying temperature, and a combination thereof.

According to one embodiment, one particular process parameter caninclude controlling the release distance 197 between a filling positionand a release position. In particular, the release distance 197 can be adistance measured in a direction 110 of the translation of the belt 109between the end of the die 103 and the initial point of separationbetween the production tool 151 and the belt 109.

After extruding the mixture 101 into the openings 152 of the productiontool 151, the belt 109 and the production tool 151 may be translated toa release zone 185 where the belt 109 and the production tool 151 can beseparated to facilitate the formation of the precursor shaped abrasiveparticles 123. In accordance with an embodiment, the production tool 151and the belt 109 may be separated from each other within the releasezone 185 at a particular release angle.

Thereafter, the precursor shaped abrasive particles 123 may betranslated through a series of optional zones wherein various treatingprocesses may be conducted. Some suitable exemplary treating processescan include drying, heating, curing, reacting, radiating, mixing,stirring, agitating, planarizing, calcining, sintering, comminuting,sieving, doping, impregnating, humidifying, application of otherabrasive particles to the body of the precursor shaped abrasiveparticles and a combination thereof. According to one embodiment, theprecursor shaped abrasive particles 123 may be translated through anoptional shaping zone 113, wherein at least one exterior surface of theparticles may be shaped as described in embodiments herein. Furthermore,the precursor shaped abrasive particles 123 may be translated through anoptional application zone 131, wherein a material, such as a dopantmaterial and/or a plurality of abrasive particles can be applied to atleast one exterior surface of the precursor shaped abrasive particles123 as described in embodiments herein.

After forming precursor shaped abrasive particles 123, the particles maybe translated through any post-forming zone 125. Various processes maybe conducted in the post-forming zone 125, including treatment of theprecursor shaped abrasive particles 123. In one embodiment, thepost-forming zone 125 can include a heating process where the precursorshaped abrasive particles 123 may be dried. Drying may include removalof a particular content of material, including volatiles, such as water.In accordance with an embodiment, the drying process can be conducted ata drying temperature of not greater than about 300° C., such as notgreater than about 280° C., or even not greater than about 250° C.Still, in one non-limiting embodiment, the drying process may beconducted at a drying temperature of at least about 50° C. It will beappreciated that the drying temperature may be within a range betweenany of the minimum and maximum temperatures noted above. Furthermore,the precursor shaped abrasive particles 123 may be translated throughthe post-forming zone 125 at a particular rate, such as at least about0.2 feet/min and not greater than about 8 feet/min.

Furthermore, the drying process may be conducted for a particularduration. For example, the drying process may be not greater than about6 hours, such as not greater than about 5 hours, not greater than about4 hours, not greater than about 2 hours, or even not greater than about1 hour. Still, the drying process may be at least about 1 minute, suchas at least about 15 minutes or at least about 30 minutes. It will beappreciated that the drying duration may be within a range between anyof the minimum and maximum temperatures noted above. For example, in atleast one embodiment, the precursor shaped abrasive particles can bedried for a duration of 1 to 10 minutes, which may facilitateintentional fracturing at a predetermined stress concentration point andalong a predetermined stress concentration vector.

After the precursor shaped abrasive particles 123 are translated throughthe post-forming zone 125, the precursor shaped abrasive particles 123may be removed from the belt 109. The precursor shaped abrasiveparticles 123 may be collected in a bin 127 for further processing.

In accordance with an embodiment, the process of forming shaped abrasiveparticles may further comprise a sintering process. For certainprocesses of embodiments herein, sintering can be conducted aftercollecting the precursor shaped abrasive particles 123 from the belt109. Alternatively, the sintering may be a process that is conductedwhile the precursor shaped abrasive particles 123 are on the belt 109.Sintering of the precursor shaped abrasive particles 123 may be utilizedto densify the particles, which are generally in a green state. In aparticular instance, the sintering process can facilitate the formationof a high-temperature phase of the ceramic material. For example, in oneembodiment, the precursor shaped abrasive particles 123 may be sinteredsuch that a high-temperature phase of alumina, such as alpha alumina, isformed. In one instance, a shaped abrasive particle can comprise atleast about 90 wt % alpha alumina for the total weight of the particle.In other instances, the content of alpha alumina may be greater suchthat the shaped abrasive particle may consist essentially of alphaalumina.

In certain instances, another post forming process can includeapplication of moisture to one or more surfaces of the gel mixture whileit resides in the openings 152 or after formation of the precursorshaped abrasive particles 123 (i.e., after the mixture is removed fromthe openings of the production tool). Application of moisture may bereferred to as humidification and may be conducted to facilitate theapplication of a plurality of particles to one or more surfaces of themixture 101 and/or precursor shaped abrasive particles 123. In at leastone embodiment, the application of moisture can include the depositionof moisture to one or more surface of the mixture while it resides inthe openings 152 of the production tool 151 and/or to the precursorshaped abrasive particles 123. In another instance, wherein applyingmoisture can include wetting the at least one surface of the mixture 101and/or precursor shaped abrasive particles 123 for a sufficient time tochange a viscosity of an exterior region of the at least one surfacerelative to a viscosity at an interior region spaced apart from theexterior region. Moreover, it is noted that the application of moisturemay facilitate gelation and sufficient bonding of the surface of themixture 101 and/or precursor shaped abrasive particles 123 with aplurality of abrasive particles. According to one embodiment, theplurality of abrasive particles can be applied to the surface of themixture 101 and/or precursor shaped abrasive particles 123 and the wateron the surface can facilitate gelation of the material of the abrasiveparticles and moistened surface for improved bonding. Reference hereinto the plurality of abrasive particles will include reference to varioustypes of particles, including but not limited to, green or unsinteredabrasive particles, sintered abrasive particles, and like.

The application of moisture can be selective, such that it is applied toat least one surface of the mixture 101 and/or precursor shaped abrasiveparticles 123, but may not necessarily be applied to another surface ofthe mixture 101 and/or precursor shaped abrasive particles 123. In oneembodiment, the application of moisture can be completed by depositionof the moisture, including for example, by spraying moisture onto one ormore surfaces of the mixture 101 and/or precursor shaped abrasiveparticles 123. In one embodiment, the application of moisture caninclude translating the mixture and/or precursor shaped abrasiveparticles through an environment having a particular moisture content.The humidity and temperature within the environment and the rate atwhich the mixture and/or precursor shaped abrasive particles 123 aretranslated through the environment may be controlled to create theparticular moisture on at least one surface of the mixture 101 and/orprecursor shaped abrasive particles 123. For example, applying moistureto the at least one surface of the mixture 101 and/or precursor shapedabrasive particles 123 can include directing a gas towards the one ormore surfaces of the mixture 101 and/or precursor shaped abrasiveparticles 123. In more particular instances, the process of applyingmoisture can include directing water vapor and/or steam at the at leastone surface of the mixture 101 and/or precursor shaped abrasiveparticles 123.

In still another embodiment, one or more devices having a particularmoisture content may contact one or more surfaces of the mixture 101and/or precursor shaped abrasive particles 123 to facilitate theapplication of moisture. For example, a sponge or other object having asuitable moisture content can contact one or more surfaces of themixture 101 and/or precursor shaped abrasive particles 123.

Still, in another embodiment, another post forming process can includechanging the viscosity of the mixture 101 and/or precursor shapedabrasive particles 123, to facilitate attachment of the plurality ofabrasive particles to at least one surface. Changing the viscosity ofthe mixture can include deposition of a second material on the surfaceof the mixture 101 and/or precursor shaped abrasive particles 123 orusing a process to alter the viscosity of the mixture 101 and/orprecursor shaped abrasive particles 123 at an exterior region. Forexample, in certain instances, changing the viscosity can includeapplication of a tacking material, such an organic or inorganic adhesivematerial. One or more of such materials may be selectively deposited onone or more surfaces of the mixture 101 and/or precursor shaped abrasiveparticles 123 to facilitate application of a plurality of abrasiveparticles to the surface.

In another embodiment, changing the viscosity can include application ofone or more viscosity modifiers that may increase or decrease theviscosity of the mixture 101 and/or precursor shaped abrasive particles123 at an exterior region compared to an interior region of the mixture101 and/or precursor shaped abrasive particles 123 that is spaced apartfrom the exterior region and is not treated with the viscosity modifier.Such a change in viscosity may be suitable for attachment of theplurality of abrasive particles.

According to one embodiment, the process of forming the abrasiveparticles can include forming a mixture 101 and/or precursor shapedabrasive particle 123 and attaching a plurality of abrasive particles toat least one surface of the mixture 101 and/or at least one surface ofthe body of the precursor shaped abrasive particle 123. In certaininstances, the process of attaching can happen in the application zone131, wherein one or more application heads 132 can facilitate depositionof the plurality of abrasive particles onto the major exterior surfaces(e.g., the upper surfaces) of the precursor shaped abrasive particles123. Various suitable processes for attaching the plurality of abrasiveparticles can include deposition processes such as blasting, projecting,pressing, gravity coating, molding, stamping, and a combination thereof.Still, it will be appreciated, that the application may happen while themixture 101 resides in the production tool 151.

According to one embodiment, the process of attaching the plurality ofabrasive particles can include forcibly projecting the plurality ofabrasive particles toward at least one surface of the mixture 101 and/orprecursor shaped abrasive particles 123. It will be appreciated thatreference herein to attaching the plurality of abrasive particles to atleast one surface can include attachment of the plurality of abrasiveparticles to a surface of the mixture 101 while the mixture is retainedin the production tool 151 (e.g., mold or screen) or after the mixture101 has been removed from the production tool 151 and the precursorshaped abrasive particles 123 have been formed. A portion or all of themixture 101 and/or precursor shaped abrasive particles 123 can have theplurality of abrasive particles attached thereto. In at least oneembodiment, forcibly projecting the plurality of abrasive particles ontothe mixture 101 or precursor shaped abrasive particles 123 includesapplying a controlled force to a deposition material including a carrierand the plurality of abrasive particles and embedding at least a portionof the plurality of abrasive particles into the surface of the mixture101 or precursor shaped abrasive particles 123. For example, thedeposition material can include a carrier, which may be a gas. Suitablegaseous materials may include water vapor, steam, an inert gas, air, ora combination thereof.

In at least one embodiment, the humidification of one or more surfacesof the mixture 101 and/or precursor shaped abrasive particles 123 anddeposition of the abrasive particles may occur separately, and morespecifically, the humidification process may happen before thedeposition process. Still, in an alternative embodiment, thehumidification process and deposition process may occur simultaneouslyas a mixture of water vapor and/or steam and the plurality of abrasiveparticles are directed to the at least one surface of the mixture 101and/or precursor shaped abrasive particles 123.

The force or pressure used to project the carrier gas and plurality ofabrasive particles may be adjusted to facilitate suitable attachment ofthe abrasive particles to the surface of the mixture 101 and/orprecursor shaped abrasive particles 123. Notably, the force or pressuremay be adapted based on one or more processing parameters, including butnot limited to, the viscosity of the surface of the mixture 101 and/orprecursor shaped abrasive particles 123, the median particle size of theplurality of abrasive particles, the content (weight or volume) of theplurality of abrasive particles being projected per unit of time, thehumidity of the environment during projecting, the temperature duringprojecting, the translation speed of the production tool or gel, thedesired level of coverage by the plurality of abrasive particles, or acombination thereof.

In at least one embodiment, the process of attaching the plurality ofabrasive particles to the bodies of the precursor shaped abrasiveparticles can occur prior to substantial drying of the body. Notably, incertain instances, some moisture in the precursor shaped abrasiveparticles may facilitate suitable attachment of the plurality ofabrasive particles. According to one embodiment, the process ofattachment can occur such that the moisture content (i.e., weightpercent of liquid) of the precursor shaped abrasive particle duringattachment can be not greater than about 70% different than the moisturecontent of the mixture 101 when it is placed in the production tool 151.The percent difference can be calculated according to the formula[(Mc1−Mc2)/Mc1]×100%, where Mc1 is the moisture content of the mixture101 during placement into the production tool 151 and Mc2 is themoisture content of the precursor shaped abrasive particle duringattachment. In other instances, the moisture content of the precursorshaped abrasive particle during attachment can be not greater than about60% different, such as not greater than about 50% different, not greaterthan about 40% different, not greater than about 30% different, notgreater than about 20% different, or even not greater than about 10%different than the moisture content of the mixture 101 when it is placedinto the production tool 151. Still, in at least one non-limitingembodiment, the moisture content of the precursor shaped abrasiveparticle during attachment can be substantially the same or exactly thesame as the moisture content of the mixture 101 when it is placed intothe production tool 151.

In at least one embodiment, the process of attaching the plurality ofabrasive particles to the bodies of the precursor shaped abrasiveparticle can include humidifying the surface of the precursor shapedabrasive particle prior to attachment of the abrasive particles. Forexample, the moisture content at the surface of the precursor shapedabrasive particles can be increased prior to the attachment process,such that the moisture content can be nearly the same as or higher thanthe moisture content of the mixture 101 when it is disposed in theproduction tool 151.

According to another embodiment, the process of attaching the pluralityof abrasive particles to the mixture 101 and/or body of the precursorshaped abrasive particles 123 can include deposition of the mixture 101onto a layer of abrasive particles including the plurality of shapedabrasive particles. For example, the production tool can be prepared tohave a layer of abrasive particles contained on a surface, onto whichthe mixture 101 is deposited and formed into a precursor shaped abrasiveparticle, such that the mixture 101 is deposited directly onto theplurality of abrasive particles. In such instances, the process ofshaping the mixture 101 into the precursor shaped abrasive particles 123and the attachment of the plurality of abrasive particles can becompleted simultaneously. For example, the upper surface of the belt 109can be prepared to contain a layer of abrasive particles and the mixture101 can be extruded into the openings 152 of the production tool 151 andonto the layer of abrasive particles on the upper surface of the belt109. The production tool 151 can then be removed from the belt 109 andthe precursor shaped abrasive particles 123 can have a plurality ofabrasive particles attached to their bottom surface, which was incontact with the belt 109. It will be appreciated that additionalprocesses can be used to attach the plurality of abrasive particles toother surfaces, including a deposition process that attaches a pluralityof abrasive particles to the upper surface of the mixture 101 and/orprecursor shaped abrasive particles 123. It is contemplated that one ormore processes can be used to attach a plurality of abrasive particlesto one or more surfaces of the mixture 101 and/or body of the precursorshaped abrasive particles 123, including but not limited to the bottomsurface, the upper surface, and side surfaces of the body of theprecursor shaped abrasive particles 123.

In yet another embodiment, the mixture 101 and/or body of the precursorshaped abrasive particles 123 can be placed into a production tool thatis translated over a substrate, wherein a plurality of abrasiveparticles are overlying the surface of the substrate. The substrate canbe stamped into the side of the production tool and the mixture 101and/or precursor shaped abrasive particles 123, such that the pluralityof abrasive particles are deposited and at least partially embeddedwithin the mixture 101 and/or precursor shaped abrasive particles 123.

According to one embodiment, the plurality of abrasive particles can beapplied or bonded to the at least one surface of the body of the mixture101 and/or precursor shaped abrasive particles 123 as unsinteredparticles. That is, the plurality of abrasive particles can be a rawmaterial, which is to undergo further processing with the mixture 101and/or precursor shaped abrasive particle 123 to form a sinteredabrasive particle on the surface of the body of the shaped abrasiveparticle. For example, the plurality of abrasive particles can include araw material including at least one material of the group of an oxide, anitride, a carbide, a boride, an oxycarbide, an oxynitride, or acombination thereof. In particular instances, the plurality of abrasiveparticles can include boehmite or pseudoboehmite material and as notedabove. The boehmite or pseudoboehmite material may be processed in thesame manner as the mixture, including the addition of seed material,pinning agents, other additives, and the like. In one particularembodiment, the plurality of abrasive particles include the samematerial as contained in the mixture used to form the body of the shapedabrasive particle.

In one embodiment, the process can include drying the precursor shapedabrasive particles and plurality of abrasive particles after attachingthe plurality of abrasive particles to the precursor shaped abrasiveparticles. Moreover, it will be appreciated that in certain instances,the process can include calcining the precursor shaped abrasive particleand plurality of abrasive particles after attaching the plurality ofabrasive particles to the precursor shaped abrasive particles. Moreover,the process can include sintering the precursor shaped abrasive particleand plurality of abrasive particles after attaching the plurality ofabrasive particles to the precursor shaped abrasive particles to form acomposite shaped abrasive particle.

FIG. 2 includes an illustration of a portion of a system for use informing shaped abrasive particles according to an embodiment. Notably,the system 150 of FIG. 2 includes some of the same components as thesystem 150 of FIG. 1A, but does not include a belt 109 underlying thetool 151. Notably, the tool 151 of FIG. 2 can be in the form of ascreen, such as illustrated in FIG. 1A, wherein the cavities 152 extendthrough the entire thickness of the tool 151. Still, it will beappreciated that the tool 151 of FIG. 2 may be formed such that thecavities 152 extend for a portion of the entire thickness of the tool151 and have a bottom surface, such that the volume of space configuredto hold and shape the mixture 101 is defined by a bottom surface andside surfaces. All processes described herein in other embodiments maybe utilized with the system illustrated in FIG. 2, including but notlimited to drying operations that may facilitate removal of the mixture101 from the cavities 152 to form precursor shaped abrasive particles.That is, the mixture 101 may undergo some appreciable drying whilecontained in the cavities 152 of the tool 151. Moreover, the process ofattaching a plurality of abrasive particles to one or more surfaces ofthe mixture 101 while it resides in the cavities or after it has beenremoved from the cavities 152 (i.e., on the surfaces of the precursorshaped abrasive particles) may be utilized with the system 150 of FIG.2.

The system of FIG. 2 may include one or more components described inU.S. Pat. No. 9,200,187. For example, the system 150 can include abacking plate underlying and abutting the tool 151 during the extrusionof the mixture into the cavities 152 of the tool 151. The backing platemay allow the cavities 152 to be filled with mixture 101. The tool 151can be translated over the backing plate such that the tool abuts thebacking plate in the deposition zone when the mixture 101 is beingdeposited in the cavities 152, and as the tool 151 is translated awayfrom the deposition zone, the tool 151 is translated away from thebacking plate.

The tool can be translated to an ejection zone, where at least oneejection assembly can be configured to direct an ejection material atthe mixture 101 contained within the cavities 152 and eject the mixture101 from the cavities to form precursor shaped abrasive particles. Theejection material may include an aerosol comprising a gas phasecomponent, a liquid phase component, a solid phase component, and acombination thereof.

FIG. 3 includes an image of an abrasive particle according to anembodiment. The abrasive particle can be a composite shaped abrasiveparticle 300 including a shaped abrasive particle having a body 301 anda plurality of abrasive particles 302 attached to at least one surface303, such as a major surface of the body 301 of the shaped abrasiveparticle. As shown, the shaped abrasive particle can have a triangulartwo-dimensional shape as viewed in a plane defined by a length (L) and awidth (W) of the body 301. However, it will be appreciated that theshaped abrasive particles can have other two dimensional shapes,including but not limited to polygons, ellipsoids, numerals, Greekalphabet characters, Latin alphabet characters, Russian alphabetcharacters, complex shapes having a combination of polygonal shapes, anda combination thereof.

According to one embodiment, shaped abrasive particle can include afirst major surface 303, a second major surface (e.g., a bottom surface)opposite the first major surface, and a side surface extending betweenthe first and second major surfaces. The plurality of abrasive particles302 can be bonded to any surface of the body, including for example, thefirst major 303 of the body 301. In other instances, the plurality ofabrasive particles 302 can be bonded to at least two surfaces of thebody. For example, the plurality of abrasive particles 302 can be bondedto at least two major surfaces of the body 301, such as those surfaceshaving the greatest surface area compared to all surfaces of the body301, which in the particle of FIG. 3 can include the first and secondmajor surfaces. In still other embodiments, the plurality of abrasiveparticles 302 can be bonded to at least two surfaces of the body 301,which can include one or more side surfaces. For example, the pluralityof abrasive particles 302 can be bonded to an upper surface and a sidesurface of the body 301. Alternatively, the plurality of abrasiveparticles 302 can be bonded to a bottom surface and a side surface ofthe body 301. It will be appreciated that in at least one embodiment,the plurality of abrasive particles 302 can be attached to all of thesurfaces of the body 301 of the shaped abrasive particle. Still, certainembodiments may utilize selective placement of the abrasive particles,such that certain surfaces (e.g., one or more major surfaces of the body301) have a plurality of abrasive particles attached thereto, but one ormore other surfaces (e.g., the side surfaces of the body 301) may beessentially free of the plurality of abrasive particles. A surface thatis essentially free of abrasive particles can include a small number ofabrasive particles, which may be accidentally deposited or bonded to thesurface, but lacks the full coverage of abrasive particles across theentire surface. For example, a surface may include not greater than 10abrasive particles and be considered essentially free of abrasiveparticles. In still another instance, a surface can have no abrasiveparticles bonded to the surface and be essentially free of abrasiveparticles. Those abrasive particles including a shaped abrasive particleand a plurality of abrasive particles attached to one or more surfacesmay be referred to as composite abrasive particles.

In certain instances, controlling the percent coverage of the pluralityof abrasive particles on the body of the shaped abrasive particle mayfacilitate improved forming, deployment, and/or performance of theabrasive particle. For certain abrasive particles of the embodimentsherein, the plurality of abrasive particles 302 can cover at least about1% of the total surface area of the body 301 of the shaped abrasiveparticle. In other instances, the plurality of abrasive particles 302covering the exterior surface of the body 301 of the shaped abrasiveparticle can be greater, such as at least about 5%, at least 10%, atleast 20%, at least 30% at least 40% at least 50%, at least 60%, atleast 70%, at least 80%, at least 90% at least 95% or even at least 99%of the total surface area of the body 301 of the shaped abrasiveparticle. Still, in at least one embodiment, the plurality of abrasiveparticles 302 can cover not greater than 99%, such as not greater than95%, not greater than 90%, not greater than 85%, not greater than 80%,not greater than 70%, not greater than 60%, not greater than 50%, notgreater than 40%, not greater than 30%, not greater than 20%, or evennot greater than 10% of the total surface area of the body 301 of theshaped abrasive particle. It will be appreciated that the plurality ofabrasive particles 302 can cover a percentage of the total surface areaof the body 301 of the shaped abrasive particle within a range includingany of the minimum and maximum percentages noted above.

For certain abrasive particles of the embodiments herein, the coverageof the plurality of particles on one surface of the body of the shapedabrasive particle may be controlled to facilitate improved forming,deployment, and/or performance of the abrasive particle. For example,the plurality of abrasive particles 302 can cover at least about 1% ofthe total surface area of an exterior surface (e.g., first majorsurface, second major surface, side surface, etc.) of the body of theshaped abrasive particle. In other instances, the percent coverage ofthe plurality of abrasive particles on a given surface of the body ofthe shaped abrasive particle can be greater, such as at least about 5%,at least 10%, at least 20%, at least 30% at least 40% at least 50%, atleast 60%, at least 70%, at least 80%, at least 90% or even at least 95%or even at least 99% or even 100% of the total surface area of the body301 of the shaped abrasive particle. Still, in at least one embodiment,the plurality of abrasive particles 302 can cover not greater than 100%such as not greater than 99% or not greater than 95%, not greater than90%, not greater than 85%, not greater than 80%, not greater than 70%,not greater than 60%, not greater than 50%, not greater than 40%, notgreater than 30%, not greater than 20%, or even not greater than 10% ofthe total surface area of the body 301 of the shaped abrasive particle.It will be appreciated that the plurality of abrasive particles 302 cancover a percentage of the total surface area of the body 301 of theshaped abrasive particle within a range including any of the minimum andmaximum percentages noted above. For example, the plurality of abrasiveparticles can cover at least 1% and not greater than 99% of the totalsurface area of the first major surface. In yet another embodiment, theplurality of abrasive particles can cover at least 30% and not greaterthan 99% of the total surface area of the first major surface. In stillanother embodiment, the plurality of abrasive particles can cover atleast 40% and not greater than 99% of the total surface area of thefirst major surface. According to another aspect, the plurality ofabrasive particles can cover at least 80% and not greater than 99% ofthe total surface area of the first major surface.

For certain abrasive particles of the embodiments herein, the coverageof the plurality of particles on one surface of the body of the shapedabrasive particle may be controlled to facilitate improved forming,deployment, and/or performance of the abrasive particle. For example, inone embodiment, the abrasive particle may include at least 10 particlesof the plurality of abrasive particles on a major surface of the body ofthe shaped abrasive particle. In still other instances, the number ofparticles of the plurality of abrasive particles on a first majorsurface of the body can be greater, such as at least 12 or at least 15or at least 18 or at least 20 or at least 22 or at least 25 or at least27 or at least 30. Still, depending upon the forming conditions, theaverage number of particles on a first major surface of the body can benot greater than 500, such as not greater than 400 or not greater than300 or not greater than 200 or not greater than 100 or not greater than80 or not greater than 60 or not greater than 50. It will be appreciatedthat the average number of abrasive particles on the first major surfaceof the body of the shaped abrasive particle can be within a rangeincluding any of the minimum and maximum values noted above. Forexample, the average number of abrasive particles can be at least 10 andnot greater than 500, such as at least 10 and not greater than 200 or atleast 15 and not greater than 200 or at least 20 and not greater than100. Furthermore, it will be appreciated that such average numbers maybe true for any other surfaces of the body of the shaped abrasiveparticle.

According to one embodiment, the plurality of abrasive particles 302 canaccount for at least 1 wt % of a total weight of the abrasive particle300, such as at least 2 wt %, at least 3 wt %, at least 4 wt %, at least5 wt %, at least 6 wt %, at least 7 wt %, at least 8 wt %, at least 9 wt%, at least 10 wt %, at least about 20 wt %, at least about 30 wt %, atleast about 40 wt %, or even at least about 50 wt %. Still, in anon-limiting embodiment, the plurality of abrasive particles 302 can benot greater than about 80 wt %, such as not greater than about 60 wt %,not greater than about 40 wt %, not greater than about 30 wt %, or evennot greater than about 20 wt %, not greater than 10 wt %, not greaterthan 8 wt %, not greater than 6 wt %, not greater than 5 wt, or notgreater than 4 wt % or even not greater than 3 wt % of a total weight ofthe abrasive particle 300. It will be appreciated that the plurality ofabrasive particles 302 can account for a particular weight percent ofthe total weight of the abrasive particle within a range including anyof the minimum and maximum percentages noted above. It will also beappreciated that such percentages can represent an average valuecalculated for a plurality of abrasive particles, wherein each of theabrasive particles include a shaped abrasive particle having a pluralityof abrasive particles bonded to at least one surface of the body of theshaped abrasive particle. Such average values are calculated from arandom and statistically relevant sample size of abrasive particles.

The weight percent of the plurality of abrasive particles can becalculated by obtaining a first sample of the particles including aminimum of 300 mg of the abrasive particles having the plurality ofabrasive particles bonded to at least one surface. The mass (M1) of theparticles is measured. The particles are spread on a flat surfaceproviding suitable contrast to accurately count the number of particles(N). A camera is used to take a picture of the particles and usingsuitable imaging software, (e.g., imageJ), the number of coatedparticles (N1) is counted. The average mass per grit (Mg1) of the grainswith the plurality of abrasive particles is calculated according to theformula Mg1=M1/N1.

The same process is conducted for a sample of particles without theplurality of abrasive particles (i.e., bare abrasive particles). Theaverage mass per grit (Mg2) is calculated for the bare sample. Theaverage weight percentage of the plurality of abrasive particles is thencalculated according to the formula 100×[(Mg2−Mg1)/Mg1].

The plurality of abrasive particles 302 may be selected from aparticular type of material to facilitate suitable formation of thecomposite shaped abrasive particles. For example, the plurality ofabrasive particles 302 can include a material from the group of oxides,carbides, nitrides, borides, oxycarbides, oxynitrides, oxyborides,natural minerals, synthetic materials, carbon-based materials, and acombination thereof. In one particular embodiment, the plurality ofabrasive particles can include alumina, and more particularly canconsist essentially of alpha alumina.

For at least one embodiment, the plurality of abrasive particles 302 caninclude a material having a particular coefficient of thermal expansion(CTE) relative to the CTE of the body 301 that can facilitate improvedforming, deployment, and/or performance of the abrasive particle. Forexample the plurality of abrasive particles 302 can have a CTE that isnot greater than about 50% different than a CTE of the body 301 of theshaped abrasive particle according to the formula[(CTE1−CTE2)/CTE1]×100%, where CTE1 represents the higher CTE valuerelative to CTE2. In certain instances, the plurality of abrasiveparticles 302 can have a CTE that is less than the CTE of the body 301.In another embodiment, the plurality of abrasive particles 302 can havea CTE that is greater than the CTE of the body 301. Still, the pluralityof abrasive particles 302 can have a CTE that is not greater than about40% different, not greater than about 30% different, not greater thanabout 20% different, or even not greater than about 10% differentcompared to the CTE of the body 301. Still, in one non-limitingembodiment, the CTE of the plurality of abrasive particles 302 may beessentially the same as the CTE of the body 301. In yet anotherembodiment, the CTE of the plurality of abrasive particles 302 can be atleast about 0.5% different, at least about 1% different, or at leastabout 3% different compared to the CTE of the body 301. It will beappreciated that the plurality of abrasive particles can have adifference in CTE relative to the CTE of the body that is within a rangeincluding any of the minimum and maximum values noted above. The CTE ofthe body of the shaped abrasive particle and the plurality of abrasiveparticles may be measured in the finally-formed abrasive particle aftersintering.

According to an embodiment, the plurality of abrasive particles 302 areselected from the group consisting of crushed grains, irregularly shapedgrains, elongated grains, agglomerates, aggregates, fine shaped abrasiveparticles, flakes, and a combination thereof. In one particularinstance, the plurality of abrasive particles consists essentially ofcrush grains, which may have a generally irregular shape. Flakes may beelongated or non-elongated grains that have a very small thicknessrelative to the width and length of the particle.

Shaped abrasive particles may be formed through particular processes,including molding, printing, casting, extrusion, and the like asdescribed herein. And will be described further herein. In at least oneembodiment, at least a portion of the plurality of abrasive particles302 may include shaped abrasive particles of a significantly finer sizecompared to the body 301 of the shaped abrasive particle 301. The shapedabrasive particles included in the plurality of abrasive particles 302overlying the body 301 of the shaped abrasive particle can have any ofthe attributes of the shaped abrasive particles defined in theembodiments herein.

The body 301 of the shaped abrasive particle can have a length (L), awidth (W) and a height (H), wherein L≥W≥H. The length may define thelongest dimension of the body 301, and in some instances may be equal tothe dimension defining the width. In one embodiment, the width cangenerally define the second longest dimension of the body 301, but incertain instances, the width can have the same value as the length. Theheight may generally define the shortest dimension of the body and mayextend in a direction perpendicular to the plane defined by the lengthand width of the body 301. According to one particular embodiment, thewidth can be greater than or equal to the height.

In accordance with an embodiment, the body 301 of the shaped abrasiveparticle can have an average particle size, as measured by the largestdimension measurable on the body 301 (i.e., the length), of at leastabout 100 microns. In fact, the body 301 of the shaped abrasive particlecan have an average particle size of at least about 150 microns, such asat least about 200 microns, at least about 300 microns, at least about400 microns, at least about 500 microns, at least about 500 microns, atleast about 600 microns, at least about 800 microns, or even at leastabout 900 microns. Still, the abrasive particle can have an averageparticle size that is not greater than about 5 mm, such as not greaterthan about 3 mm, not greater than about 2 mm, or even not greater thanabout 1.5 mm. It will be appreciated that the abrasive particle can havean average particle size within a range including any of the minimum andmaximum values noted above.

The abrasive grains (i.e., crystallites) contained within the body ofthe shaped abrasive particles or the plurality of abrasive particles mayhave an average grain size that is generally not greater than about 100microns. In other embodiments, the average grain size can be less, suchas not greater than about 80 microns, not greater than about 50 microns,not greater than about 30 microns, not greater than about 20 microns,not greater than about 10 microns, not greater than about 1 micron, notgreater than about 0.9 microns, not greater than about 0.8 microns, notgreater than about 0.7 microns, or even not greater than about 0.6microns. Still, the average grain size of the abrasive grains containedwithin the body of the abrasive particles can be at least about 0.01microns, such as at least about 0.05 microns, at least about 0.06microns, at least about 0.07 microns, at least about 0.08 microns, atleast about 0.09 microns, at least about 0.1 microns, at least about0.12 microns, at least about 0.15 microns, at least about 0.17 microns,at least about 0.2 microns, or even at least about 0.5 microns. It willbe appreciated that the abrasive grains can have an average grain sizewithin a range between any of the minimum and maximum values notedabove.

The plurality of abrasive particles 302 may have a particular medianparticle size relative to one or more dimensions of the body 301 of theshaped abrasive particle. For example, the plurality of abrasiveparticles 302 can have a median particle size (D50) that can be notgreater than the length (L) of the body 301 of the shaped abrasiveparticle. More particularly, the plurality of abrasive particles 302 canhave a median particle size (D50) that is not greater than about 90% ofthe length (L), such as not greater than about 80% of the length, notgreater than about 70% of the length, not greater than about 60% of thelength, not greater than about 50% of the length, not greater than about40% of the length, not greater than about 30% of the length, not greaterthan about 25% of the length, not greater than about 20% of the length,not greater than about 18% of the length, not greater than about 15% ofthe length, not greater than about 12% of the length, not greater thanabout 10% of the length, not greater than about 8% of the length, notgreater than about 6% of the length, or even not greater than about 5%of the length of the body 301. Still, in another non-limitingembodiment, the plurality of abrasive particles 302 can have a medianparticle size (D50) that is at least about 0.1% of the length (L), suchas at least about 0.5% of the length, at least about 1% of the length,or even at least about 2% of the length, at least about 3% of thelength, at least about 4% of the length, at least about 5% of thelength, at least about 6% of the length, at least about 7% of thelength, at least about 8% of the length, at least about 9% of thelength, at least about 10% of the length, at least about 12% of thelength, at least about 15% of the length, at least about 18% of thelength, at least about 20% of the length, at least about 25% of thelength, or even at least about 30% of the length of the body 301. Itwill be appreciated that the plurality of abrasive particles 302 canhave a median particle size (D50) that is within a range including anyof the minimum and maximum percentages noted above.

According to one particular embodiment, the plurality of abrasiveparticles 302 can have a median particle size (D50) that is at least0.1% and not greater than about 90% of the length (L) of the body of theshaped abrasive particle, which can be calculated by [(D50)/(L)]×100%.In another embodiment, the plurality of abrasive particles 302 can havea median particle size (D50) of at least 0.1% and not greater than about50% of the length of the body, such as at least 0.1% and not greaterthan about 20% or at least 0.1% and not greater than about 10% or atleast 0.1% and not greater than about 8% or at least 0.1% and notgreater than about 6%, or at least 0.1% and not greater than about 5% oreven at least 1% and not greater than 5% of the length of the body ofthe shaped abrasive particle. Moreover, it has been noted in certaininstances, that the relative median particle size (D50) of the pluralityof abrasive particles 302 compared to the length of the body may impactthe percent coverage of the abrasive particles on the body.

In another embodiment, the plurality of abrasive particles 302 can havea median particle size (D50) that is not greater than about 90% of thewidth (W), such as not greater than about 80% of the width, not greaterthan about 70% of the width, not greater than about 60% of the width,not greater than about 50% of the width, not greater than about 40% ofthe width, not greater than about 30% of the width, not greater thanabout 25% of the width, not greater than about 20% of the width, notgreater than about 18% of the width, not greater than about 15% of thewidth, not greater than about 12% of the width, not greater than about10% of the width, not greater than 8% of the width, not greater than 6%of the width, or even not greater than 5% of the width of the body 301.Still, in another non-limiting embodiment, the plurality of abrasiveparticles 302 can have a median particle size (D50) that is at leastabout 0.1% of the width (W), such as at least about 0.5% of the width,at least about 1% of the width, at least about 2% of the width, at leastabout 3% of the width, at least about 4% of the width, at least about 5%of the width, at least about 6% of the width, at least about 7% of thewidth, at least about 8% of the width, at least about 9% of the width,at least about 10% of the width, at least about 12% of the width, atleast about 15% of the width, at least about 18% of the width, at leastabout 20% of the width, at least about 25% of the width, at least about30% of the width of the body 301. It will be appreciated that theplurality of abrasive particles 302 can have a median particle size(D50) that is within a range including any of the minimum and maximumpercentages noted above.

According to one particular embodiment, the plurality of abrasiveparticles 302 can have a median particle size (D50) that is at least0.1% and not greater than about 90% of the width of the body of theshaped abrasive particle, which can be calculated by [(D50)/(W)]×100. Inanother embodiment, the plurality of abrasive particles 302 can have amedian particle size (D50) of at least 0.1% and not greater than about50% of the width of the body, such as at least 0.1% and not greater thanabout 20% or at least 0.1% and not greater than about 10% or at least0.1% and not greater than about 8% or at least 0.1% and not greater thanabout 6%, or at least 1% and not greater than about 6% or even at least1% and not greater than 4% of the width of the body of the shapedabrasive particle. Moreover, it has been noted in certain instances,that the relative median particle size (D50) of the plurality ofabrasive particles 302 compared to the width of the body may impact thepercent coverage of the abrasive particles on the body.

In another embodiment, the plurality of abrasive particles 302 can havea median particle size (D50) that is not greater than about 90% of theheight, such as not greater than about 80% of the height, not greaterthan about 70% of the height, not greater than about 60% of the height,not greater than about 50% of the height, not greater than about 40% ofthe height, not greater than about 30% of the height, not greater thanabout 25% of the height, not greater than about 20% of the height, notgreater than about 18% of the height, not greater than about 15% of theheight, not greater than about 12%, the height, not greater than about10% of the height, not greater than about 8% of the height, not greaterthan about 6% of the height, not greater than about 5% of the height ofthe body 301. Still, in another non-limiting embodiment, the pluralityof abrasive particles 302 can have a median particle size (D50) that isat least about 0.1% of the height, such as at least about 0.5% of theheight, at least about 1% of the height, at least about 2% of theheight, at least about 3% of the height, at least about 4% of theheight, at least about 5% of the height, at least about 6% of theheight, at least about 7% of the height, at least about 8% of theheight, at least about 9% of the height, at least about 10% of theheight, at least about 12% of the height, at least about 15% of theheight, at least about 18% of the height, at least about 20% of theheight, at least about 25% of the height, at least about 30% of theheight of the body 301. It will be appreciated that the plurality ofabrasive particles 302 can have a median particle size (D50) that iswithin a range including any of the minimum and maximum percentagesnoted above.

According to one particular embodiment, the plurality of abrasiveparticles 302 can have a median particle size (D50) that is at least0.1% and not greater than about 90% of the height of the body of theshaped abrasive particle, which can be calculated by [(D50)/(H)]×100. Inanother embodiment, the plurality of abrasive particles 302 can have amedian particle size (D50) of at least 0.1% and not greater than about50% of the height of the body, such as at least 0.1% and not greaterthan about 20% or at least 1% and not greater than about 18% or at least5% and not greater than about 18% or at least 8% and not greater thanabout 16% of the height of the body of the shaped abrasive particle.Moreover, it has been noted in certain instances, that the relativemedian particle size (D50) of the plurality of abrasive particles 302compared to the height of the body may impact the percent coverage ofthe abrasive particles on the body.

In accordance with an embodiment, the plurality of abrasive particles302 can have a median particle size (D50) of not greater than about 1mm, such as not greater than about 800 microns, not greater than about500 microns or not greater than 300 microns or not greater than 200microns or not greater than 100 microns or not greater than 90 micronsor not greater than 80 microns or not greater than 70 microns or notgreater than 65 microns or not greater than 60 microns or not greaterthan 50 microns or even not greater than 40 microns. Still, in onenon-limiting embodiment, the plurality of abrasive particles 302 canhave a median particle size (D50) of at least about 0.1 microns, such asat least about 0.5 microns or at least 1 micron or at least 2 microns orat least 3 microns or at least 5 microns or at least 10 microns or atleast 15 microns or at least 20 microns or at least 25 microns or atleast 30 microns. It will be appreciated that the abrasive particle canhave a median particle size within a range including any of the minimumand maximum values noted above. For example, the plurality of abrasiveparticles can have a median particle size (D50) of at least 0.1 micronsand not greater than 500 microns or at least 0.5 microns and not greaterthan 100 microns or at least 1 micron and not greater than 65 microns.It has been noted in certain instances, that the median particle size(D50) of the plurality of abrasive particles 302 may impact theformation, deployment, and/or performance of the abrasive particles.

For at least one embodiment, at least a portion of the abrasiveparticles of the plurality of abrasive particles can be at leastpartially embedded in at least one surface the body 301 of the shapedabrasive particle. Moreover, in certain instances, the portion caninclude a majority of the abrasive particles of the plurality ofabrasive particles 302 that can be at least partially embedded in atleast one surface of the body 301 of the shaped abrasive particle.According to another embodiment, the portion of the plurality ofabrasive particles can be a minority of the particles of the pluralityof abrasive particles that are at least partially embedded within atleast one surface of the body 301. It will be appreciated that embeddedparticles can extend into the volume of the body below an exteriorsurface of the body 301, as opposed to particles that are overlying thesurface of the body 301, but may not be embedded and extending into thevolume of the body 301 (e.g., particles that are applied as a certaintype of coating). Moreover, the feature of the embedded abrasiveparticles is distinct from patterned surface features, such as groovesor rounded protrusions, wherein the abrasive particles are embedded intothe volume of the body of the shaped abrasive particle, and theplurality of abrasive particles have sharp and irregular corners (e.g.,in the context of crushed and irregular shaped abrasive particles)protruding from the surface. Without wishing to be tied to a particulartheory, it is thought that the sharp and irregular surfaces of theplurality of abrasive particles, as well as the random distribution ofthe abrasive particles on the surface of the shaped abrasive particlemay impact the self-sharpening behavior of the composite abrasiveparticle, and thus may improve the performance of the abrasive particleand associated abrasive article. The plurality of abrasive particles mayalso facilitate improved retention of the abrasive particles in certainbond matrix materials, including for example in the bonding layers of acoated abrasive or within the three-dimensional volume of a bondmaterial within a bonded abrasive article.

According to one embodiment, at least one of the abrasive particles ofthe plurality of abrasive particles can be attached to a surface of thebody of the shaped abrasive particle and define an acute contact angle.Notably, the provision of the plurality of abrasive particles accordingto the processes herein can facilitate the attachment of one or more ofthe abrasive particles of the plurality abrasive particles to the bodyin a manner that defines an acute angle. A random sample of abrasiveparticles can be obtained. Each abrasive particle may be sectioned orground transverse to the longitudinal axis through the middle half ofthe body. To obtain a suitable view of the cross-section, such asillustrated in FIG. 10, wherein the body of the shaped abrasive particle1001 is clearly shown and the plurality of abrasive particles 1002attached to at least one major surface 1004 are also visible. Each ofthe abrasive particles can be mounted in an epoxy resin, which is curedand solidified. After mounting each of the abrasive particles in theepoxy resin, a wafer slicing saw can be used to cut out each of theabrasive particles and a portion of the epoxy surrounding each of theabrasive particles, such that discrete samples are formed and include awhole abrasive particle surrounded by a mass of epoxy. Each sample isthen polished to remove a portion of the grain and expose the transverseplane used to evaluate the contact area of the grains that exposed. Thetransverse plane should be smooth such that the perimeter of theresulting cross-sectional is well defined. If necessary, the resultingcross-sectional plane can be polished to a uniform height.

After completing the foregoing preparation of the samples, each abrasiveparticle can be mounted and viewed by an optical microscope (e.g.,Olympus DSX500) at 10× magnification with a field of view of 2 mm. Usingthe optical microscope, an image of the cross-section of each abrasiveparticle is obtained, such as provided in FIG. 11. Using a suitableimaging program, such as ImageJ (available from the National Instituteof Health), the contact angle created by abutting surfaces of theabrasive particles and the surface of the body are measured.

Referring to FIG. 11, the abrasive particle 1101 can form a contactangle 1102 with the major surface 1103 of the body 1104. Notably, atleast a portion of the abrasive particles create a contact angle withthe body that is less than 90 degrees. For example, the abrasiveparticle contact angle can be less than 88 degrees, such as less than 85degrees or less than 80 degrees or less than 75 degrees or less than 70degrees or less than 65 degrees or less than 60 degrees or less than 55degrees or less than 50 degrees or less than 45 degrees or less than 40degrees or less than 35 degrees or less than 30 degrees or less than 25degrees or less than 20 degrees or less than 15 degrees or less than 10degrees or less than 5 degrees. In yet another embodiment, the abrasiveparticle contact angle can be at least 1 degree or at least 5 degrees orat least 10 degrees or at least 15 degrees or at least 20 degrees or atleast 25 degrees or at least 30 degrees or at least 35 degrees or atleast 40 degrees. It will be appreciated that the abrasive particlecontact angle can be within a range including any of the minimum andmaximum values noted above.

In another embodiment, at least a portion of the plurality of abrasiveparticles 302 can be bonded directly to at least one surface of the body301 of the shaped abrasive particle. More particularly, at least aportion of the plurality of abrasive particles 302 can be sinter-bondedto at least one surface of the body 301 of the shaped abrasive particle.In at least one embodiment, all of the abrasive particles of theplurality of abrasive particles 302 can be sinter-bonded to at least onesurface of the body 301 of the shaped abrasive particle.

FIG. 4 includes a three-dimensional image of an upper surface of anabrasive particle according to an embodiment. As illustrated, theabrasive particle 400 includes a body 401 having an upper surface 402with a plurality of abrasive particles attached thereto. As illustratedin the three-dimensional mapping image, the plurality of abrasiveparticles creates an upper surface having a rough contour with aplurality of randomly arranged peaks and valleys. Such a rough contourmay facilitate improved bonding of the abrasive particle in variousfixed abrasive articles relative to shaped abrasive particles withsmooth surfaces. Moreover, the rough and varied contour of the uppersurface 402 may facilitate improved abrasive performance in variousfixed abrasives, as a greater number of sharp abrasive surfaces arepresent as compared to a conventional, smooth surfaced shaped abrasiveparticle. In certain instances, the existence of the rough contour maylimit the need to deploy the abrasive particle in a particularorientation, which is generally the desired approach for conventionalshaped abrasive particles, particularly in coated abrasive articles.Still, in other embodiments, it may be advantageous to deploy theabrasive particles in a particular orientation in a fixed abrasive,wherein the one or more surfaces including the plurality of abrasiveparticles have a controlled orientation relative to one or morereferences axes within the fixed abrasive article.

According to one embodiment, the plurality of abrasive particles can beattached to the first major surface and the first major surface can havea surface roughness greater than a surface roughness of another surface(e.g., a side surface) of the body that has fewer abrasive particlesattached thereto. In one particular embodiment, the first major surfacecan include a plurality of abrasive particles bonded thereto and thebody can be essentially free of any abrasive particles bonded to theside surface, and in such instances, the surface roughness of the firstmajor surface can be significantly greater than the side surface.Surface roughness can be measured using any suitable techniques,including for example optical metrology techniques. In yet anotherembodiment, the first major surface can include a plurality of abrasiveparticles bonded thereto and the body can be essentially free of anyabrasive particles bonded to the second major surface, and in suchinstances, the surface roughness of the first major surface can besignificantly greater than the second major surface.

FIG. 5 includes a perspective view illustration of a shaped abrasiveparticle in accordance with an embodiment. The shaped abrasive particle500 can include a body 501 including a major surface 502, a majorsurface 503, and a side surface 504 extending between the major surfaces502 and 503. As illustrated in FIG. 5, the body 501 of the shapedabrasive particle 500 is a thin-shaped body, wherein the major surfaces502 and 503 are larger than the side surface 504. Moreover, the body 501can include an axis 510 extending from a point to a base and through themidpoint 550 on the major surface 502. The axis 510 can define thelongest dimension of the major surface extending through the midpoint550 of the major surface 502, which may be the length or width of thebody depending on the geometry, but in the illustrated embodiment ofFIG. 5 defines the width. The body 501 can further include an axis 511defining a dimension of the body 501 extending generally perpendicularto the axis 510 on the same major surface 502, which in the illustratedembodiment of an equilateral triangle defines the length of the body501. Finally, as illustrated, the body 501 can include a vertical axis512, which in the context of thin shaped bodies can define a height (orthickness) of the body 501. For thin-shaped bodies, the length of theaxis 510 is equal to or greater than the vertical axis 512. Asillustrated, the height 512 can extend along the side surface 504between the major surfaces 502 and 503 and perpendicular to the planedefined by the axes 510 and 511. It will be appreciated that referenceherein to length, width, and height of the abrasive particles may bereferenced to average values taken from a suitable sampling size ofabrasive particles of a batch of abrasive particles.

The shaped abrasive particles can include any of the features of theabrasive particles of the embodiments herein. For example, the shapedabrasive particles can include a crystalline material, and moreparticularly, a polycrystalline material. Notably, the polycrystallinematerial can include abrasive grains. In one embodiment, the body of theabrasive particle, including for example, the body of a shaped abrasiveparticle can be essentially free of an organic material, including forexample, a binder. In at least one embodiment, the abrasive particlescan consist essentially of a polycrystalline material.

Some suitable materials for use as abrasive particles can includenitrides, oxides, carbides, borides, oxynitrides, oxyborides, diamond,carbon-containing materials, and a combination thereof. In particularinstances, the abrasive particles can include an oxide compound orcomplex, such as aluminum oxide, zirconium oxide, titanium oxide,yttrium oxide, chromium oxide, strontium oxide, silicon oxide, magnesiumoxide, rare-earth oxides, and a combination thereof. In one particularembodiment, the abrasive particles can include at least 95 wt % aluminafor the total weight of the body. In at least one embodiment, theabrasive particles can consist essentially of alumina. Still, in certaininstances, the abrasive particles can include not greater than 99.5 wt %alumina for the total weight of the body. Moreover, in particularinstances, the shaped abrasive particles can be formed from a seededsol-gel. In at least one embodiment, the abrasive particles of theembodiments herein may be essentially free of iron, rare-earth oxides,and a combination thereof.

In accordance with certain embodiments, certain abrasive particles canbe compositional composite articles including at least two differenttypes of grains within the body of the shaped abrasive particle orwithin the body of the abrasive particles of the plurality of abrasiveparticles. It will be appreciated that different types of grains aregrains having different compositions with regard to each other. Forexample, the body of the shaped abrasive particle can be formed suchthat is includes at least two different types of grains, wherein the twodifferent types of grains can be nitrides, oxides, carbides, borides,oxynitrides, oxyborides, carbon-based materials, diamond, naturallyoccurring minerals, rare-earth-containing materials, and a combinationthereof.

FIG. 5 includes an illustration of a shaped abrasive particle having atwo-dimensional shape as defined by the plane of the upper major surface502 or major surface 503, which has a generally triangulartwo-dimensional shape, such as an equilateral triangle. It will beappreciated that the shaped abrasive particles of the embodiments hereinare not so limited and can include other two-dimensional shapes. Forexample, the shaped abrasive particles of the embodiment herein caninclude particles having a body with a two-dimensional shape as definedby a major surface of the body from the group of shapes includingpolygons, irregular polygons, irregular polygons including arcuate orcurved sides or portions of sides, ellipsoids, numerals, Greek alphabetcharacters, Latin alphabet characters, Russian alphabet characters,Kanji characters, complex shapes having a combination of polygonsshapes, star shapes, shapes with arms extending from a central region(e.g., cross-shaped bodies) and a combination thereof.

It will also be appreciated that the shaped abrasive particles need notbe limited to thin shapes defined by only a two-dimensional shape of amajor surface, but can include three-dimensional shapes. For example,the body can have a three-dimensional shape selected from the groupconsisting of a polyhedron, a pyramid, an ellipsoid, a sphere, a prism,a cylinder, a cone, a tetrahedron, a cube, a cuboid, a rhombohedrun, atruncated pyramid, a truncated ellipsoid, a truncated sphere, atruncated cone, a pentahedron, a hexahedron, a heptahedron, anoctahedron, a nonahedron, a decahedron, a Greek alphabet letter, a Latinalphabet character, a Russian alphabet character, a Kanji character,complex polygonal shapes, irregular shaped contours, a volcano shape, amonostatic shape, and a combination thereof. A monostatic shape is ashape with a single stable resting position. Accordingly, shapedabrasive particles having a monostatic shape can be applied to asubstrate and consistently be oriented in the same position, as theyhave only one stable resting position. For example, shaped abrasiveparticles having a monostaic shape may be suitable when applying theparticles to a backing via gravity coating, which may be used in theformation of a coated abrasive product. More particularly, the shapedabrasive particles may be mono-monostatic shapes, which describe threedimensional objects having a shape with only one unstable point ofbalance. According to one particular embodiment, the shaped abrasiveparticle may have the shape of a gomboc. In another embodiment, theshaped abrasive particle is a monostatic polyhedron with at least foursurfaces.

FIG. 6A includes a perspective view illustration of a shaped abrasiveparticle according to an embodiment. Notably, the shaped abrasiveparticle 600 can include a body 601 including a surface 602 and asurface 603, which may be referred to as end surfaces 602 and 603. Thebody can further include surfaces 604, 605, 606, 607 extending betweenand coupled to the end surfaces 602 and 603. The shaped abrasiveparticle of FIG. 6A is an elongated shaped abrasive particle having alongitudinal axis 610 that extends along the surface 605 and through themidpoint 640 between the end surfaces 602 and 603. It will beappreciated that the surface 605 is selected for illustrating thelongitudinal axis 610, because the body 601 has a generally squarecross-sectional contour as defined by the end surfaces 602 and 603. Assuch, the surfaces 604, 605, 606, and 607 have approximately the samesize relative to each other. However in the context of other elongatedabrasive particles, wherein the surfaces 602 and 603 define a differentshape, for example a rectangular shape, wherein one of the surfaces 604,605, 606, and 607 may be larger relative to the others, the largestsurface of those surfaces defines the major surface, and therefore thelongitudinal axis would extend along the largest of those surfaces. Asfurther illustrated, the body 601 can include a lateral axis 611extending perpendicular to the longitudinal axis 610 within the sameplane defined by the surface 605. As further illustrated, the body 601can further include a vertical axis 612 defining a height of theabrasive particle, wherein the vertical axis 612 can extend in adirection perpendicular to the plane defined by the longitudinal axis610 and lateral axis 611 of the surface 605.

It will be appreciated that like the thin shaped abrasive particle ofFIG. 5, the elongated shaped abrasive particle of FIG. 6A can havevarious two-dimensional shapes such as those defined with respect to theshaped abrasive particle of FIG. 5. The two-dimensional shape of thebody 601 can be defined by the shape of the perimeter of the endsurfaces 602 and 603. The elongated shaped abrasive particle 600 canhave any of the attributes of the shaped abrasive particles of theembodiments herein.

FIG. 6B includes an illustration of an elongated particle, which is anon-shaped abrasive particle. Shaped abrasive particles may be formedthrough particular processes, including molding, printing, casting,extrusion, and the like. Shaped abrasive particles are formed such thateach particle has substantially the same arrangement of surfaces andedges relative to each other for shaped abrasive particles having thesame two-dimensional and three-dimensional shapes. As such, shapedabrasive particles can have a high shape fidelity and consistency in thearrangement of the surfaces and edges relative to other shaped abrasiveparticles of the group having the same two-dimensional andthree-dimensional shape. By contrast, non-shaped abrasive particles canbe formed through different process and have different shape attributes.For example, non-shaped abrasive particles are typically formed by acomminution process, wherein a mass of material is formed and thencrushed and sieved to obtain abrasive particles of a certain size.However, a non-shaped abrasive particle will have a generally randomarrangement of the surfaces and edges, and generally will lack anyrecognizable two-dimensional or three dimensional shape in thearrangement of the surfaces and edges around the body. Moreover,non-shaped abrasive particles of the same group or batch generally lacka consistent shape with respect to each other, such that the surfacesand edges are randomly arranged when compared to each other. Therefore,non-shaped grains or crushed grains have a significantly lower shapefidelity compared to shaped abrasive particles.

As further illustrated in FIG. 6B, the elongated abrasive article can bea non-shaped abrasive particle having a body 651 and a longitudinal axis652 defining the longest dimension of the particle, a lateral axis 653extending perpendicular to the longitudinal axis 652 and defining awidth of the particle. Furthermore, the elongated abrasive particle mayhave a height (or thickness) as defined by the vertical axis 654, whichcan extend generally perpendicular to a plane defined by the combinationof the longitudinal axis 652 and lateral axis 653. As furtherillustrated, the body 651 of the elongated, non-shaped abrasive particlecan have a generally random arrangement of edges 655 extending along theexterior surface of the body 651.

As will be appreciated, the elongated abrasive particle can have alength defined by longitudinal axis 652, a width defined by the lateralaxis 653, and a vertical axis 654 defining a height. As will beappreciated, the body 651 can have a primary aspect ratio oflength:width such that the length is greater than the width.Furthermore, the length of the body 651 can be greater than or equal tothe height. Finally, the width of the body 651 can be greater than orequal to the height 654. In accordance with an embodiment, the primaryaspect ratio of length:width can be at least 1.1:1, at least 1.2:1, atleast 1.5:1, at least 1.8:1, at least 2:1, at least 3:1, at least 4:1,at least 5:1, at least 6:1, or even at least 10:1. In anothernon-limiting embodiment, the body 651 of the elongated shaped abrasiveparticle can have a primary aspect ratio of length:width of not greaterthan 100:1, not greater than 50:1, not greater than 10:1, not greaterthan 6:1, not greater than 5:1, not greater than 4:1, not greater than3:1, or even not greater than 2:1. It will be appreciated that theprimary aspect ratio of the body 651 can be with a range including anyof the minimum and maximum ratios noted above. It will be appreciatedthat not all non-shaped abrasive particles are elongated abrasiveparticles, and some non-shaped abrasive particles can be substantiallyequiaxed, such that any combination of the length, width, and height aresubstantially the same. The non-shaped abrasive particles can be used asthe plurality of abrasive particles overlying and bonded to the surfaceof the shaped abrasive particle. It will be appreciated that thenon-shaped abrasive particles may also be used as the body of theabrasive particle to which the plurality of abrasive particles isbonded.

Furthermore, the body 651 of the elongated abrasive particle 650 caninclude a secondary aspect ratio of width:height that can be at least1.1:1, such as at least 1.2:1, at least 1.5:1, at least 1.8:1, at least2:1, at least 3:1, at least 4:1, at least 5:1, at least 8:1, or even atleast 10:1. Still, in another non-limiting embodiment, the secondaryaspect ratio width:height of the body 651 can be not greater than 100:1,such as not greater than 50:1, not greater than 10:1, not greater than8:1, not greater than 6:1, not greater than 5:1, not greater than 4:1,not greater than 3:1, or even not greater than 2:1. It will beappreciated the secondary aspect ratio of width:height can be with arange including any of the minimum and maximum ratios of above.

In another embodiment, the body 651 of the elongated abrasive particle650 can have a tertiary aspect ratio of length:height that can be atleast 1.1:1, such as at least 1.2:1, at least 1.5:1, at least 1.8:1, atleast 2:1, at least 3:1, at least 4:1, at least 5:1, at least 8:1, oreven at least 10:1. Still, in another non-limiting embodiment, thetertiary aspect ratio length:height of the body 651 can be not greaterthan 100:1, such as not greater than 50:1, not greater than 10:1, notgreater than 8:1, not greater than 6:1, not greater than 5:1, notgreater than 4:1, not greater than 3:1, It will be appreciated that thetertiary aspect ratio the body 651 can be with a range including any ofthe minimum and maximum ratios and above.

The elongated abrasive particle 650 can have certain attributes of theother abrasive particles described in the embodiments herein, includingfor example, but not limited to, composition, microstructural features(e.g., average grain/crystallite size), hardness, porosity, and thelike.

FIG. 7A includes a top view illustration of a shaped abrasive particleaccording to an embodiment. In particular, the shaped abrasive particle700 can include a body 701 having the features of other shaped abrasiveparticles of embodiments herein, including an upper major surface 703and a bottom major surface (not shown) opposite the upper major surface703. The upper major surface 703 and the bottom major surface can beseparated from each other by at least one side surface 705, which mayinclude one or more discrete side surface portions, including forexample, a first portion 706 of the side surface 705, a second portion707 of the side surface 705, and a third portion 708 of the side surface705. In particular, the first portion 706 of the side surface 705 canextend between a first corner 709 and a second corner 710. The secondportion 707 of the side surface 705 can extend between the second corner710 and a third corner 711. Notably, the second corner 710 can be anexternal corner joining two portions of the side surface 705. The secondcorner 710 and a third corner 711, which are also external corners, areadjacent to each other and have no other external corners disposedbetween them. Also, the third portion 708 of the side surface 705 canextend between the third corner 711 and the first corner 709, which areboth external corners that are adjacent to each other and have no otherexternal corners disposed between them.

As illustrated, the body 701 can include a first portion 706 including afirst curved section 742 disposed between a first linear section 741 anda second linear section 743 and between the external corners 709 and710. The second portion 707 is separated from the first portion 706 ofthe side surface 705 by the external corner 710. The second portion 707of the side surface 705 can include a second curved section 752 joininga third linear section 751 and a fourth linear section 753. Furthermore,the body 701 can include a third portion 708 separated from the firstportion 706 of the side surface 705 by the external corner 709 andseparated from the second portion 707 by the external corner 711. Thethird portion 708 of the side surface 705 can include a third curvedsection 762 joining a fifth linear section 761 and a sixth linearsection 763.

FIG. 7B includes a top view of a shaped abrasive particle 730 accordingto an embodiment. The tip sharpness of a shaped abrasive particle, whichmay be an average tip sharpness, may be measured by determining theradius of a best fit circle on an external corner 731 of the body 732.For example, turning to FIG. 7B, a top view of the upper major surface733 of the body 732 is provided. At an external corner 731, a best fitcircle is overlaid on the image of the body 732 of the shaped abrasiveparticle 730, and the radius of the best fit circle relative to thecurvature of the external corner 731 defines the value of tip sharpnessfor the external corner 731. The measurement may be recreated for eachexternal corner of the body 732 to determine the average individual tipsharpness for a single shaped abrasive particle 730. Moreover, themeasurement may be recreated on a suitable sample size of shapedabrasive particles of a batch of shaped abrasive particles to derive theaverage batch tip sharpness. Any suitable computer program, such asImageJ may be used in conjunction with an image (e.g., SEM image orlight microscope image) of suitable magnification to accurately measurethe best fit circle and the tip sharpness.

The shaped abrasive particles of the embodiments herein may have aparticular tip sharpness that may facilitate suitable performance in thefixed abrasive articles of the embodiments herein. For example, the bodyof a shaped abrasive particle can have a tip sharpness of not greaterthan 80 microns, such as not greater than 70 microns, not greater than60 microns, not greater than 50 microns, not greater than 40 microns,not greater than 30 microns, not greater than 20 microns, or even notgreater than 10 microns. In yet another non-limiting embodiment, the tipsharpness can be at least 2 microns, such as at least 4 microns, atleast 10 microns, at least 20 microns, at least 30 microns, at least 40microns, at least 50 microns, at least 60 microns, or even at least 70microns. It will be appreciated that the body can have a tip sharpnesswithin a range between any of the minimum and maximum values notedabove.

Another grain feature of shaped abrasive particles is the Shape Index.The Shape Index of a body of a shaped abrasive particle can be describedas a value of an outer radius of a best-fit outer circle superimposed onthe body, as viewed in two dimensions of a plane of length and width ofthe body (e.g., the upper major surface or the bottom major surface),compared to an inner radius of the largest best-fit inner circle thatfits entirely within the body, as viewed in the same plane of length andwidth. For example, turning to FIG. 7C the shaped abrasive particle 770is provided with two circles superimposed on the illustration todemonstrate the calculation of Shape Index. A first circle issuperimposed on the body 770, which is a best-fit outer circlerepresenting the smallest circle that can be used to fit the entireperimeter of the body 770 within its boundaries. The outer circle has aradius (Ro). For shapes such as that illustrated in FIG. 7C, the outercircle may intersect the perimeter of the body at each of the threeexternal corners. However, it will be appreciated that for certainirregular or complex shapes, the body may not fit uniformly within thecircle such that each of the corners intersect the circle at equalintervals, but a best-fit, outer circle still may be formed. Anysuitable computer program, such as ImageJ may be used in conjunctionwith an image of suitable magnification (e.g., SEM image or lightmicroscope image) to create the outer circle and measure the radius(Ro).

A second, inner circle can be superimposed on the body 770, asillustrated in FIG. 7C, which is a best fit circle representing thelargest circle that can be placed entirely within the perimeter of thebody 770 as viewed in the plane of the length and width of the body 770.The inner circle can have a radius (Ri). It will be appreciated that forcertain irregular or complex shapes, the inner circle may not fituniformly within the body such that the perimeter of the circle contactsportions of the body at equal intervals, such as shown for the shape ofFIG. 7C. However, a best-fit, inner circle still may be formed. Anysuitable computer program, such as ImageJ may be used in conjunctionwith an image of suitable magnification (e.g., SEM image or lightmicroscope image) to create the inner circle and measure the radius(Ri).

The Shape Index can be calculated by dividing the outer radius by theinner radius (i.e., Shape Index=Ri/Ro). For example, the body 770 of theshaped abrasive particle has a Shape Index of approximately 0.35.Moreover, an eqilateral triangle generally has a Shape Index ofapproximately 0.5, while other polygons, such as a hexagon or pentagonhave Shape Index values greater than 0.5. In accordance with anembodiment, the shaped abrasive particles herein can have a Shape Indexof at least 0.15, at least 0.20, at least 0.25, at least 0.30, at least0.35, at least 0.40, at least 0.45, at least about 0.5, at least about0.55, at least 0.60, at least 0.65, at least 0.70, at least 0.75, atleast 0.80, at least 0.85, at least 0.90, at least 0.95. Still, inanother non-limiting embodiment, the shaped abrasive particle can have aShape Index of not greater than 1, such as not greater than 0.98, notgreater than 0.95, not greater than 0.90, not greater than 0.85, notgreater than 0.80, not greater than 0.75, not greater than 0.70, notgreater than 0.65, not greater than 0.60, not greater than 0.55, notgreater than 0.50, not greater than 0.45, not greater than 0.40, notgreater than 0.35, not greater than 0.30, not greater than 0.25, notgreater than 0.20, or even not greater than 0.15. It will be appreciatedthat the shaped abrasive particles can have a Shape Index within a rangebetween any of the minimum and maximum values noted above.

FIG. 7D includes a top view of a shaped abrasive particle according toanother embodiment. The shaped abrasive particle 780 can have a body 781having the features of other shaped abrasive particles of embodimentsherein, including an upper major surface 783 and a bottom major surface(not shown) opposite the upper major surface 783. The upper majorsurface 783 and the bottom major surface can be separated from eachother by at least one side surface 784, which may include one or morediscrete side surface sections. According to one embodiment, the body781 can be defined as an irregular hexagon, wherein the body has ahexagonal (i.e., six-sided) two dimensional shape as viewed in the planeof a length and a width of the body 781, and wherein at least two of thesides, such as sides 785 and 786, have a different length with respectto each other. Notably, the longest dimension along one of the sides isunderstood herein to refer to the width of the body 781 and the lengthof the body is the longest dimension extending through the midpoint ofthe body 781 from one side of the body to the other (e.g., from a cornerto a flat side opposite the corner). Moreover, as illustrated, none ofthe sides are parallel to each other. And furthermore, while notillustrated, any of the sides may have a curvature to them, including aconcave curvature wherein the sides may curve inwards toward theinterior of the body 781.

FIG. 8 includes a cross-sectional view of a portion of an abrasiveparticle according to an embodiment. As illustrated, the abrasiveparticle can include a shaped abrasive particle including a body 801having a first major surface 802, a second major surface 803, and sidesurface 804 and 805 extending between the first and second major surface802 and 803 as viewed in cross-section. The abrasive particle 800 canfurther include a plurality of abrasive particles coupled to certainsurfaces of the body 801 of the shaped abrasive particle. The pluralityof abrasive particles can include one or more portions of particles,which may be differentiated as groups of abrasive particles, wherein thedifferent groups may have at least one abrasive characteristic that isdistinct from each other. Abrasive characteristics can include but isnot limited to average particle size, average crystallite size,hardness, toughness, two-dimensional shape, three-dimensional shape,shaped abrasive particles, non-shaped abrasive particles, composition,standing angle, orientation, and a combination thereof. Utilization ofdifferent groups may facilitate tailoring of the abrasive particles fora given application. Additionally, different groups may or may not becoupled to different surfaces of the body 801 of the shaped abrasiveparticle. That is, in one embodiment, the same single surface of thebody 801 can include a plurality of groups of abrasive particles. Instill other embodiments, the body 801 of the shaped abrasive particlecan have different groups of abrasive particles coupled to differentsurfaces of the body 801.

In particular, the abrasive particle 800 can include a plurality ofabrasive particles including a first group of abrasive particles 810attached to a portion of the first major surface 802. The first group ofabrasive particles 810 can include fine shaped abrasive particles 811having an average particle size significantly less than the averageparticle size of the body 801 of the shaped abrasive particle. The fineshaped abrasive particles can have any of the attributes of other shapedabrasive particles as described in the embodiments herein. In oneparticular embodiment, the fine shaped abrasive particles can have atwo-dimensional shape that is substantially the same as the twodimensional shape of the body of the shaped abrasive particle. Still inanother embodiment, the fine shaped abrasive particles can have atwo-dimensional shape that is different than the two dimensional shapeof the body of the shaped abrasive particle. It will also be appreciatedthat the fine shaped abrasive particles can have any of thethree-dimensional shapes as described herein.

Notably, the fine shaped abrasive particles can have a median particlesize relative to the length, width, and/or height of the body 801. Thesame relationship noted herein with respect to the median particle sizeof the plurality of abrasive particles relative to the length, width, orheight of the body of the shaped abrasive particles can be true when theplurality of abrasive particles includes fine shaped abrasive particles.The fine shaped arbasive particles have a length<width<height, whereinthe average length of the fine shaped abrasive particles is less thanthe length of the body of the shaped abrasive particle.

For example, the fine shaped abrasive particles 810 can have an averagelength of not greater than about 90% of the length of the body 801, suchas or not greater than about 80% of the length or not greater than about70% of the length or not greater than about 60% of the length or notgreater than about 50% of the length or not greater than about 40% ofthe length or not greater than about 30% of the length or not greaterthan 25% of the length or not greater than 20% of the length or notgreater than about 18% of the length or not greater than about 15% ofthe length or not greater than about 12% of the length or not greaterthan about 10% of the length or not greater than 8% of the length or notgreater than 6% of the length or not greater than 5% of the length ofthe body 801 of the shaped abrasive particle. In still anothernon-limiting embodiment, the fine shaped abrasive particles 811 have anaverage length of at least about 0.1% of the length of the body 801 orat least about 0.5% of the length or at least about 1% of the length orat least about 2% of the length or at least about 3% of the length or atleast about 4% of the length or at least about 5% of the length or atleast about 6% of the length or at least about 7% of the length or atleast about 8% of the length or at least about 9% of the length or atleast about 10% of the length or at least about 12% of the length or atleast about 15% of the length or at least about 18% of the length or atleast about 20% of the length or at least about 25% of the length or atleast about 30% of the length of the body 801 of the shaped abrasiveparticle. It will be appreciated that the average length of the fineshaped abrasive particles can be within a range between any of theminimum and maximum percentages noted above.

Additionally, the fine shaped abrasive particles can have a particularaverage width that is less than the length of the body 801 of the shapedabrasive particle. According to one embodiment, the fine shaped abrasiveparticles 811 can have an average width that is not greater than about90% of the length of the body 801, such as not greater than about 80% ofthe length or not greater than about 70% of the length or not greaterthan about 60% of the length or not greater than about 50% of the lengthor not greater than about 40% of the length or not greater than about30% of the length or not greater than about 25% of the length or notgreater than about 20% of the length or not greater than about 18% ofthe length or not greater than about 15% of the length or not greaterthan about 12% of the length or not greater than about 10% of the lengthor not greater than about 8% of the length or not greater than about 6%of the length or not greater than about 5% of the length of the body ofthe shaped abrasive particle. Still, in another embodiment, the fineshaped abrasive particles 811 can have an average width of at leastabout 0.1% of the length of the body 801, such as at least about 0.5% ofthe length or at least about 1% of the length or at least about 2% ofthe length or at least about 3% of the length or at least about 4% ofthe length or at least about 5% of the length or at least about 6% ofthe length or at least about 7% of the length or at least about 8% ofthe length or at least about 9% of the length or at least about 10% ofthe length or at least about 12% of the length or at least about 15% ofthe length or at least about 18% of the length or at least about 20% ofthe length or at least about 25% of the length or at least about 30% ofthe length of the body of the shaped abrasive particle. It will beappreciated that the average width of the fine shaped abrasive particlescan be within a range between any of the minimum and maximum percentagesnoted above.

For yet another embodiment, the fine shaped abrasive particles 811 canhave an average height that is less than the length of the body 801 ofthe shaped abrasive particle. For example, the fine shaped abrasiveparticles 811 can have an average height that is not greater than about90% of the length of the body 801, such as not greater than about 80% ofthe length or not greater than about 70% of the length or not greaterthan about 60% of the length or not greater than about 50% of the lengthor not greater than about 40% of the length or not greater than about30% of the length or not greater than about 25% of the length or notgreater than about 20% of the length or not greater than about 18% ofthe length or not greater than about 15% of the length or not greaterthan about 12% of the length or not greater than about 10% of the lengthor not greater than about 8% of the length or not greater than about 6%of the length or not greater than about 5% of the length of the body 801of the shaped abrasive particle. Still, in one non-limiting embodiment,the fine shaped abrasive particles 811 can have an average height of atleast about 0.01% of the length of the body 801, such as at least about0.1% of the length or at least about 0.5% of the length or at leastabout 1% of the length or at least about 2% of the length or at leastabout 3% of the length or at least about 4% of the length or at leastabout 5% of the length or at least about 6% of the length or at leastabout 7% of the length or at least about 8% of the length or at leastabout 9% of the length or at least about 10% of the length or at leastabout 12% of the length or at least about 15% of the length or at leastabout 18% of the length or at least about 20% of the length or at leastabout 25% of the length or at least about 30% of the length of the body801 of the shaped abrasive particle. It will be appreciated that theaverage height of the fine shaped abrasive particles can be within arange between any of the minimum and maximum percentages noted above.

FIG. 8, it will be appreciated that a majority of the plurality ofabrasive particles overlying the body 801 can be fine shaped abrasiveparticles. Moreover, in certain instances, essentially all of theabrasive particles of the plurality of abrasive particles overlying thebody 801 can be fine shaped abrasive particles.

The composite shaped abrasive particle 800 can further include a secondgroup of abrasive particles 812 also attached to the first major surface802 of the body 801. The second group of abrasive particles 812 can benon-shaped abrasive particles 813. According to one embodiment, asillustrated in FIG. 8, at least one surface of the body 801, such as thefirst major surface 802 of the abrasive particle 800 can have a blend oftwo different types of abrasive particles. The first and second groupsof abrasive particles 810 and 812 can be placed on the first majorsurface 802 using any of the techniques described herein. The first andsecond group of abrasive particles 810 and 812 may be deposited on thefirst major surface 802 simultaneously or separately.

Moreover, the first group of abrasive particles 810 can have a firstaverage particles size, which in the case of fine shaped abrasiveparticles can be defined by the average length, and the second group ofabrasive particles 812 can have a second average particle size, which inthe case of fine shaped abrasive particles can be defined by the averagelength. In certain instances the first and second average particle sizescan be different from one another. In still another embodiment, thefirst and second average particle sizes can be substantially the same.The relative sizes of the abrasive particles 811 and 813 of the firstand second groups of abrasive particles 810 and 812 can be tailoreddepending upon the desired application of the abrasive particles.

As further illustrated, abrasive particle 800 can include a third groupof abrasive particles 817 that can be coupled to the second majorsurface 803 of the body 801. The third group of abrasive particles 817can include fine shaped abrasive particles 818, which can have asignificantly smaller average particle sized compared to the body 801 ofthe shaped abrasive particle. The fine shaped abrasive particles 818 canhave a different two-dimensional shaped compared to the shaped abrasiveparticles 811 of the first group of abrasive particles 810.

Moreover, at least a portion of the fine shaped abrasive particles 818may be oriented in a standing position relative the surface 803 of thebody 801 of the shaped abrasive particle. While the group of abrasiveparticles 817 is illustrated as shaped abrasive particles, it will beappreciated that it may also include elongated abrasive particles, whichmay be shaped or non-shaped, and can be oriented in a standing positionrelative to the surface 803 of the body 801. According to an embodiment,the standing orientation can be defined by a largest surface (i.e., amajor) of the body of a fine shaped abrasive particle being spaced apartfrom the surface of the body of the shaped abrasive particle. Moreover,the standing orientation of the fine shaped abrasive particles 818 canbe defined by a standing angle 820 between the longitudinal axis 819 ofthe fine shaped abrasive particle 820 (or elongated abrasive particle,shaped or non-shaped) and the major surface 803 of the body 801. Thestanding angle 820 can be at least 5 degrees, such as at least 10degrees, at least 20 degrees, at least 30 degrees, or at least 40degrees or at least 50 degree or at least 60 degrees or at least 70degrees or at least 80 degrees or at least 85 degrees. In at least oneembodiment, the fine shaped abrasive particles 818 are in a standingorientation relative to the surface 803 of the body 801 and define asubstantially perpendicular standing angle 820 as illustrated in FIG. 8.

Still, in another embodiment, the group of abrasive particles 817 caninclude a portion of abrasive particles 830 that are lying flat. In alying flat orientation, the longitudinal axis of the abrasive particles831 may be substantially parallel to the surface 803 of the body 801.

FIG. 9 includes a top down illustration of an abrasive particleaccording to an embodiment. As illustrated, the abrasive particle 900can include a shaped abrasive particle having a body 901 and a pluralityof abrasive particles 940 overlying and bonded to a major surface 905 ofthe body 901. As illustrated, according to one embodiment, the pluralityof abrasive particles 940 can be arranged on one or more surfaces of thebody 901 in one or more distributions.

As illustrated, in one embodiment, the plurality of abrasive particles940 may include different groups. For example, the plurality of abrasiveparticles 940 may include a first group of abrasive particles 902, whichmay include fine shaped abrasive particles 903 that can be arranged in acontrolled distribution on the surface 905 of the body 901. The fineshaped abrasive particles 903 can be lying flat relative to the surface905 of the body 905. The fine shaped abrasive particles 903 can bearranged in a pattern defined by a plurality of repeating units, whereineach repeating unit of the plurality of repeating units is substantiallythe same with respect to each other. As illustrated in the embodiment,the fine shaped abrasive particles 903 are arranged in a pattern definedby a substantially triangular repeating unit, as shown by the dottedline. In at least one embodiment, the abrasive particle 900 can beformed such that the fine abrasive particles 903 may extend over amajority or over substantially the entire surface 905 of the body 901 inthe controlled distribution as illustrated. It will be appreciated thatthis may be true of any of the groups of abrasive particles asillustrated herein. Still, in certain instances, one or more groups ofabrasive particles may be overlying and bonded to the same surface ofthe body 901 and may define different distributions and/or orientationsrelative to each other.

According to another embodiment, the plurality of abrasive particles 940can include a second group of abrasive particles 910, which may includefine shaped abrasive particles 911 that can be arranged in a randomdistribution on the surface 905 of the body 901. The fine shapedabrasive particles 911 can be in a standing orientation relative to thesurface 905 of the body 905. The fine shaped abrasive particles 911 lackany identifiable repeating unit and thus are arranged in a substantiallyrandom distribution compared to each other. It will be appreciated thatother types of abrasive particles can be used and other orientation ofthe abrasive particles may be used. In at least one embodiment, theabrasive particle 900 can be formed such that the fine abrasiveparticles 911 may extend over a majority or over substantially theentire surface 905 of the body 901 in the random distribution asillustrated.

In yet another embodiment, the plurality of abrasive particles 940 caninclude a third group of abrasive particles 920, which may include fineshaped abrasive particles 921 that can be arranged in a controlleddistribution on the surface 905 of the body 901. The fine shapedabrasive particles 921 can be in a standing orientation relative to thesurface 905 of the body 905. As illustrated in the embodiment, the fineshaped abrasive particles 921 can be arranged in a pattern defined by asubstantially rectangular repeating unit as shown by the dotted line. Inat least one embodiment, the abrasive particle 900 can be formed suchthat the fine abrasive particles 903 may extend over a majority or oversubstantially the entire surface 905 of the body 901 in the controlleddistribution as illustrated. It will be appreciated that other types ofabrasive particles can be used and other orientation of the abrasiveparticles may be used.

For still another embodiment, the plurality of abrasive particles 940can include a fourth group of abrasive particles 930, which may includenon-shaped abrasive particles 931 that can be arranged in a randomdistribution on the surface 905 of the body 901. The non-shaped abrasiveparticles 931 can be in a substantially random arrangement relative toeach other. In at least one embodiment, the abrasive particle 900 can beformed such that the non-shaped abrasive particles 931 may extend over amajority or over substantially the entire surface 905 of the body 901 inthe random distribution as illustrated.

In at least one embodiment, at least a portion of the plurality ofabrasive particles of an abrasive particle can have a coating overlyingat least a portion of the exterior surfaces of the abrasive particles.The coating may include a material selected from the group of inorganic,organic, amorphous, crystalline, polycrystalline, ceramic, metal, resin,epoxy, polymer, oxides, carbides, nitrides, borides, carbon-basedmaterials, and a combination thereof.

According to an embodiment, the abrasive particles of the embodimentsherein can have a particularly rough and jagged surface. It has beennoted by some in the industry that abrasive particles having smoothsurfaces and sharp edges provide the best performance. However it hasbeen surprisingly discovered by the Applicants of the present disclosurethat grains having a rough surface by virtue of the plurality ofabrasive particles attached thereto can have improved performancecompared to grains without a plurality of grains attached to one or moresurfaces (i.e., grains having a smoother surface).

In at least one particular embodiment, the abrasive particle can includea body of a shaped abrasive particle having a first major surface and asecond major surface separated from the first major surface by a sidesurface, wherein the plurality of abrasive particles are attached to atleast the first major surface or the second major surface and the sidesurface is essentially free of the plurality of abrasive particles. Instill other instances, the abrasive particle can include a body of ashaped abrasive particle having a first major surface and a second majorsurface separated from the first major surface by a side surface, andwherein the plurality of abrasive particles are attached to the firstmajor surface and the second major surface and the side surface isessentially free of the plurality of abrasive particles. Still, it willbe appreciated that the plurality of abrasive particles may be overlyingand bonded to one or more of the side surface of the body of the shapedabrasive particle.

FIG. 12A includes a cross-sectional illustration of a coated abrasivearticle incorporating the abrasive particulate material in accordancewith an embodiment. Notably, the plurality of abrasive particles on theone or more surfaces of the abrasive particles are not illustrated, butwill be appreciated as being present in accordance with embodimentsherein. As illustrated, the coated abrasive 1200 can include a substrate1201 and a make coat 1203 overlying a surface of the substrate 1201. Thecoated abrasive 1200 can further include a first type of abrasiveparticulate material 1205 in the form of a first type of shaped abrasiveparticle, a second type of abrasive particulate material 1206 in theform of a second type of shaped abrasive particle, and a third type ofabrasive particulate material in the form of diluent abrasive particles,which may not necessarily be shaped abrasive particles, and having arandom shape. The coated abrasive 1200 may further include size coat1204 overlying and bonded to the abrasive particulate materials 1205,1206, 1207, and the make coat 1204.

According to one embodiment, the substrate 1201 can include an organicmaterial, inorganic material, and a combination thereof. In certaininstances, the substrate 1201 can include a woven material. However, thesubstrate 1201 may be made of a non-woven material. Particularlysuitable substrate materials can include organic materials, includingpolymers, and particularly, polyester, polyurethane, polypropylene,polyimides such as KAPTON from DuPont, paper. Some suitable inorganicmaterials can include metals, metal alloys, and particularly, foils ofcopper, aluminum, steel, and a combination thereof.

The make coat 1203 can be applied to the surface of the substrate 1201in a single process, or alternatively, the abrasive particulatematerials 1205, 1206, 1207 can be combined with a make coat 1203material and applied as a mixture to the surface of the substrate 1201.Suitable materials of the make coat 1203 can include organic materials,particularly polymeric materials, including for example, polyesters,epoxy resins, polyurethanes, polyamides, polyacrylates,polymethacrylates, poly vinyl chlorides, polyethylene, polysiloxane,silicones, cellulose acetates, nitrocellulose, natural rubber, starch,shellac, and mixtures thereof. In one embodiment, the make coat 1203 caninclude a polyester resin. The coated substrate can then be heated inorder to cure the resin and the abrasive particulate material to thesubstrate. In general, the coated substrate 1201 can be heated to atemperature of between about 100° C. to less than about 250° C. duringthis curing process.

Moreover, it will be appreciated that the coated abrasive article caninclude one or more collections of various types of abrasive particles,including the abrasive particulate materials 1205, 1206, and 1207, whichmay represent the abrasive particles of the embodiments herein. Theembodiments herein can include a fixed abrasive article (e.g., a coatedabrasive article) having a first collection of abrasive particles (e.g.,abrasive particulate materials 1205) representative of the abrasiveparticles of the embodiments herein. Any fixed abrasive may furtheremploy a second collection of abrasive particles therein, which may berepresentative of another type of abrasive particle according to theembodiments herein, which may be distinct in one or more manners fromthe abrasive particles of the first collection, including but notlimited to, one or more abrasive characteristics as described herein.The same features may be utilized in a bonded abrasive article.

The abrasive particulate materials 1205, 1206, and 1207 can includedifferent types of shaped abrasive particles according to embodimentsherein. The different types of shaped abrasive particles can differ fromeach other in composition, two-dimensional shape, three-dimensionalshape, size, and a combination thereof as described in the embodimentsherein. As illustrated, the coated abrasive 1200 can include a firsttype of shaped abrasive particle 1205 having a generally triangulartwo-dimensional shape and a second type of shaped abrasive particle 1206having a quadrilateral two-dimensional shape. The coated abrasive 1200can include different amounts of the first type and second type ofshaped abrasive particles 1205 and 1206. It will be appreciated that thecoated abrasive may not necessarily include different types of shapedabrasive particles, and can consist essentially of a single type ofshaped abrasive particle. As will be appreciated, the shaped abrasiveparticles of the embodiments herein can be incorporated into variousfixed abrasives (e.g., bonded abrasives, coated abrasive, non-wovenabrasives, thin wheels, cut-off wheels, reinforced abrasive articles,and the like), including in the form of blends, which may includedifferent types of shaped abrasive particles, shaped abrasive particleswith diluent particles, and the like. Moreover, according to certainembodiments, a batch of particulate material may be incorporated intothe fixed abrasive article in a predetermined orientation, wherein eachof the shaped abrasive particles can have a predetermined orientationrelative to each other and relative to a portion of the abrasive article(e.g., the backing of a coated abrasive).

The abrasive particles 1207 can be diluent particles different than thefirst and second types of shaped abrasive particles 1205 and 1206. Forexample, the diluent particles can differ from the first and secondtypes of shaped abrasive particles 1205 and 1206 in composition,two-dimensional shape, three-dimensional shape, size, and a combinationthereof. For example, the abrasive particles 1207 can representconventional, crushed abrasive grit having random shapes. The abrasiveparticles 1207 may have a median particle size less than the medianparticle size of the first and second types of shaped abrasive particles1205 and 1206.

After sufficiently forming the make coat 503 with the abrasiveparticulate materials 1205, 1206, 1207 contained therein, the size coat1204 can be formed to overlie and bond the abrasive particulate material1205 in place. The size coat 1204 can include an organic material, maybe made essentially of a polymeric material, and notably, can usepolyesters, epoxy resins, polyurethanes, polyamides, polyacrylates,polymethacrylates, poly vinyl chlorides, polyethylene, polysiloxane,silicones, cellulose acetates, nitrocellulose, natural rubber, starch,shellac, and mixtures thereof.

FIG. 12B includes a perspective view illustration of a portion of acoated abrasive article including an abrasive particle according to anembodiment. Notably, the illustrated embodiment of FIG. 12B includes anabrasive article 1230 including an abrasive particle 1231 including ashaped abrasive particle 1232 having a body including a plurality ofabrasive particles 1234 bonded to a first major surface 1235 of the bodyof the shaped abrasive particle. Notably the coated abrasive articleincludes a backing 1236 having a longitudinal axis 1237 and a lateralaxis 1238. In one embodiment, the abrasive particle 1231 is placed onthe backing 1236 and can be bonded on the backing 1236 in a particularorientation using one or more adhesive layers (e.g., a make coat, sizecoat, etc.) as noted herein. In certain instances, the abrasive particle1231 can be placed in a controlled orientation on the backing 1236, suchthat the orientation of the first major surface 1235 including theplurality of shaped abrasive particles 1234 has a particular orientationrelative to the longitudinal axis 1237 and/or lateral axis 1238 of thebacking 1236. For example, in certain instances, such as for theabrasive particle 1232, the first major surface 1235 including theplurality of abrasive particles 1234 can be oriented substantiallyperpendicular to the longitudinal axis 1237 and substantially parallelto the lateral axis 1238. In certain other instances, an alternativeorientation may be desired, including for example, an abrasive particle1241 having a plurality of abrasive particles 1242 attached to a firstmajor surface 1243 of the body of the shaped abrasive particle 1244,wherein the particle has a controlled orientation including the firstmajor surface 1243 being substantially perpendicular to the lateral axis1238 and substantially parallel to the longitudinal axis 1237. It willbe appreciated that the abrasive particles can also have othercontrolled orientations, such that the orientation of one or moreabrasive particles on the backing can define a controlled angle relativeto the lateral axis 1238 and/or longitudinal axis 1237. Moreover, theorientation of the abrasive particles may be controlled depending uponthe number and/or type of surfaces of the shaped abrasive particle(i.e., first major surface and/or second major surface and/or sidesurface) that are covered. Moreover, the coated abrasive article caninclude one or more group of abrasive particles on the backing 1236,wherein each group of abrasive particles can have at least one abrasivecharacteristic that is similar relative to each other. Suitable examplesof certain types of abrasive characteristics include type of coating ofthe plurality of abrasive particles, size of the plurality of abrasiveparticles, shape of the body of the shaped abrasive particle,composition of the shaped abrasive particle and/or plurality of abrasiveparticle, orientation, tilt angle, and any of the other features ofembodiments detailed herein. Moreover, abrasive particles from differentgroups on the backing can differ in at least one of the abrasivecharacteristics noted herein.

FIG. 13A includes an illustration of a bonded abrasive articleincorporating the abrasive particulate material in accordance with anembodiment. As illustrated, the bonded abrasive 1300 can include a bondmaterial 1301, abrasive particulate material 1302 contained in the bondmaterial, and porosity 1308 within the bond material 1301. In particularinstances, the bond material 1301 can include an organic material,inorganic material, and a combination thereof. Suitable organicmaterials can include polymers, such as epoxies, resins, thermosets,thermoplastics, polyimides, polyamides, and a combination thereof.Certain suitable inorganic materials can include metals, metal alloys,vitreous phase materials, crystalline phase materials, ceramics, and acombination thereof.

The abrasive particulate material 1302 of the bonded abrasive 1300 caninclude different types of shaped abrasive particles 1303, 1304, 1305,and 1306, which can have any of the features of different types ofshaped abrasive particles as described in the embodiments herein.Notably, the different types of shaped abrasive particles 1303, 1304,1305, and 1306 can differ from each other in composition,two-dimensional shape, three-dimensional shape, size, and a combinationthereof as described in the embodiments herein.

The bonded abrasive 1300 can include a type of abrasive particulatematerial 1307 representing diluent abrasive particles, which can differfrom the different types of shaped abrasive particles 1303, 1304, 1305,and 1306 in composition, two-dimensional shape, three-dimensional shape,size, and a combination thereof.

The porosity 1308 of the bonded abrasive 1300 can be open porosity,closed porosity, and a combination thereof. The porosity 1308 may bepresent in a majority amount (vol %) based on the total volume of thebody of the bonded abrasive 1300. Alternatively, the porosity 1308 canbe present in a minor amount (vol %) based on the total volume of thebody of the bonded abrasive 1300. The bond material 1301 may be presentin a majority amount (vol %) based on the total volume of the body ofthe bonded abrasive 1300. Alternatively, the bond material 1301 can bepresent in a minor amount (vol %) based on the total volume of the bodyof the bonded abrasive 1300. Additionally, abrasive particulate material1302 can be present in a majority amount (vol %) based on the totalvolume of the body of the bonded abrasive 1300. Alternatively, theabrasive particulate material 1302 can be present in a minor amount (vol%) based on the total volume of the body of the bonded abrasive 1300.

FIG. 13B includes an illustration of a bonded abrasive article includingabrasive particles of the embodiments herein. As illustrated, the bondedabrasive 1350 can include a body 1351 including an abrasive particle1360 and abrasive particle 1370 contained within the bond matrixmaterial 1352 of the body 1351. The abrasive particle 1360 can include ashaped abrasive particle 1361 and a plurality of abrasive particles 1362bonded to at least a first major surface 1363 of the body of the shapedabrasive particle 1361. Notably, the abrasive particle 1360 can have aparticular position within the three dimensional volume of the body 1351of the bonded abrasive 1350. Moreover, the abrasive particle 1360 canhave a controlled and predetermined orientation relative to a radialaxis 1381 and/or lateral axis 1382 of the body 1351. According to oneembodiment, the abrasive particle 1360 can have an orientation that isconsidered to be lying flat within the body 1351 as the first majorsurface 1363 of the body of the shaped abrasive particle 1361 issubstantially parallel to the radial axis 1381 or substantially parallelto the major surfaces 1354 and 1355 of the body 1351 of the bondedabrasive 1350. Moreover, the first major surface 1363 of the shapedabrasive particle 1361 can be substantially perpendicular to the lateralaxis 1382. In certain instances, a bonded abrasive may include a portionof abrasive particles within the body in the orientation like theabrasive particle 1360, which may facilitate improved formation of thebonded abrasive and/or improve performance of the bonded abrasive.

As further illustrated, the abrasive particle 1370 can include a shapedabrasive particle 1371 and a plurality of abrasive particles 1372 bondedto at least a first major surface 1373 of the body of the shapedabrasive particle 1371. Notably, the abrasive particle 1370 can have aparticular position within the three dimensional volume of the body 1351of the bonded abrasive 1350. Moreover, the abrasive particle 1370 canhave a controlled and predetermined orientation relative to a radialaxis 1381 and/or lateral axis 1382 of the body 1351. According to oneembodiment, the abrasive particle 1360 can have an orientation that isconsidered to be standing upright within the body 1351 as the firstmajor surface 1373 of the body of the shaped abrasive particle 1371 issubstantially parallel to the lateral axis 1382 and substantiallyperpendicular to the major surfaces 1354 and 1355 of the body 1351 ofthe bonded abrasive 1350. Moreover, the first major surface 1373 of theshaped abrasive particle 1371 can be substantially perpendicular to theradial axis 1381. In other instances, the abrasive particle 1370 can beoriented within the body 1351 such that it is tilted with respect to thelateral axis to define a controlled tilt angle. In such situations, theabrasive particle 1371 may have a first major surface that is neithersubstantially perpendicular to the radial axis 1381 nor substantiallyparallel to the lateral axis. Such a controlled tilt angle can includeany angle between 5 degrees and 85 degrees. As used herein, reference toa substantially parallel or substantially perpendicular orientation isreference to a difference between an axis or plane and a reference axisof not greater than 5 degrees. Moreover, as will be appreciated, theabrasive particles can have various rotational orientations about thelateral axis 1382 and the radial axis 1381. When referring to a tiltangle, it will be understood that there may be a radial tilt angledefined as the smallest angle formed between the radial axis 1381 and aradial vector defining the direction of the major surface having thelargest component in the radial direction. There may also be a lateraltilt angle defined as the smallest angle formed between the lateral axis1382 and a vector defining the direction of the major surface with thelargest component in the lateral direction.

Many different aspects and embodiments are possible. Some of thoseaspects and embodiments are described herein. After reading thisspecification, skilled artisans will appreciate that those aspects andembodiments are only illustrative and do not limit the scope of thepresent invention. Embodiments may be in accordance with any one or moreof the items as listed below.

Items

Item 1. An abrasive particle comprising a shaped abrasive particlecomprising a body, and a plurality of abrasive particles bonded to atleast one surface of the body of the shaped abrasive particle.

Item 2. The abrasive particle of item 1, wherein the body of the shapedabrasive particle comprises a two-dimensional shape as viewed in a planedefined by a length and a width of the body selected from the groupconsisting of polygons, ellipsoids, numerals, Greek alphabet characters,Latin alphabet characters, Russian alphabet characters, complex shapeshaving a combination of polygonal shapes, and a combination thereof.

Item 3. The abrasive particle of item 1, wherein the plurality ofabrasive particles is bonded to a major surface of the body or whereinthe plurality of abrasive particles is bonded to at least two surfacesof the body or wherein the plurality of abrasive particles is bonded toat least two major surfaces of the body.

Item 4. The abrasive particle of item 1, wherein wherein a portion ofthe particles of the plurality of abrasive particles is embedded intothe volume of the body of the shaped abrasive particle or wherein aportion of the abrasive particles of the plurality of abrasive particlesis embedded within the at least one surface of the body or wherein theplurality of abrasive particles are sinter-bonded to the at least onesurface of the body of the shaped abrasive particle or wherein a portionof the abrasive particles of the plurality of abrasive particles aresinter-bonded to the at least one surface of the body of the shapedabrasive particle.

Item 5. The abrasive particle of item 4, wherein wherein the portionincludes a minority of the particles of the plurality of abrasiveparticles or wherein the portion includes a majority of the particles ofthe plurality of abrasive particles.

Item 6. The abrasive particle of item 1, wherein the plurality ofabrasive particles cover at least 1% of the total surface area of thebody or at least 5% or at least 10% or at least 20% or at least 30% orat least 40% or at least 50% or at least 60% or at least about 70% or atleast about 80% or at least about 90% or at least about 95%, and whereinthe plurality of abrasive particles cover not greater than 95% or notgreater than 90% or not greater than 80% or not greater than 60% or notgreater than 50% or not greater than 40% or not greater than 30% or thetotal surface area of the body.

Item 7. The abrasive particle of item 1, wherein the body includes afirst major surface, a second major surface, and a side surfaceextending between the first major surface and the second major surface,wherein the plurality of abrasive particles is bonded to the first majorsurface and the side surface is essentially free of abrasive particlesof the plurality of abrasive particles.

Item 8. The abrasive particle of item 1, wherein the surface of the bodyincluding the plurality of abrasive particle comprises a randomarrangement of the plurality of abrasive particles on a major surface ofthe body, and wherein a side surface of the body is essentially free ofthe plurality of abrasive particles.

Item 9. The abrasive particle of item 1, wherein wherein the bodycomprises a first major surface and a second major surface separatedfrom the first major surface by a side surface, wherein the plurality ofabrasive particles are attached to the first major surface and the firstmajor surface has a surface roughness greater than a surface roughnessof the side surface.

Item 10. The abrasive particle of item 1, wherein the plurality ofabrasive particles are selected from the group consisting of oxides,carbides, nitrides, borides, oxycarbides, oxynitrides, oxyborides,natural minerals, synthetic materials, carbon-based materials, and acombination thereof.

Item 11. The abrasive particle of item 1, wherein the plurality ofabrasive particles are selected from the group consisting of crushedgrains, irregularly shaped grains, elongated grains, agglomerates,aggregates, and a combination thereof.

Item 12. The abrasive particle of item 1, wherein the body of the shapedabrasive particle comprises a length>width>height, and the plurality ofabrasive particles comprise a median particle size (D50), and whereinthe median particle size (D50) is not greater than the length of thebody of the shaped abrasive particle or wherein the median particle size(D50) is not greater than the width of the body of the shaped abrasiveparticle or wherein the median particle size (D50) is not greater thanthe height of the body of the shaped abrasive particle.

Item 13. The abrasive particle of item 12, wherein the plurality ofabrasive particles comprise a median particle size (D50) of not greaterthan about 90% of the length of the body or at least about 0.1% of thelength of the body.

Item 14. The abrasive particle of item 1, wherein the plurality ofabrasive particles comprise comprise at least 1 wt % of a total weightof the abrasive particle or wherein the plurality of abrasive particlescomprise not greater than about 80 wt % of a total weight of theabrasive particle.

Item 15. The abrasive particle of item 12, wherein the median particlesize (D50) is not greater than the width of the body of the shapedabrasive particle or wherein the plurality of abrasive particlescomprise a median particle size (D50) of not greater than about 90% ofthe width of the body or at least about 0.1% of the width of the body.

Item 16. The abrasive particle of item 1, wherein the plurality ofabrasive particles include a material having a CTE that is not greaterthan about 50% different than a CTE of the body of the shaped abrasiveparticle.

Item 17. The abrasive particle of item 15, wherein the median particlesize (D50) is not greater than the height of the body of the shapedabrasive particle or wherein the plurality of abrasive particlescomprise a median particle size (D50) of not greater than about 90% ofthe height of the body or at least about 0.1% of the height of the body.

Item 18. The abrasive particle of item 1, wherein at least a portion ofthe plurality of abrasive particles include fine shaped abrasiveparticles, or wherein essentially all of the plurality of abrasiveparticles include the fine shaped abrasive particles.

Item 19. The abrasive particle of item 18, wherein the fine shapedarbasive particles have a length<width<height, wherein the averagelength of the fine shaped abrasive particles is less than the length ofthe body of the shaped abrasive particle.

Item 20. The abrasive particle of item 19, wherein fine shaped abrasiveparticles comprise an average length of not greater than about 90% ofthe length of the body or at least about 0.1% of the length of the bodyof the shaped abrasive particle.

Item 21. The abrasive particle of item 19, wherein the fine shapedabrasive particles comprise an average width that is less than thelength of the body of the shaped abrasive particle or wherein the fineshaped abrasive particles comprise an average height that is less thanthe length of the body of the shaped abrasive particle.

Item 22. The abrasive particle of item 19, wherein a portion of the fineshaped abrasive particles are positioned in a standing orientationrelative to the surface of the body of the shaped abrasive particle.

Item 23: The abrasive particle of item 1, wherein the plurality ofabrasive particles is arranged on the surface of the body in a randomdistribution.

Item 24. The abrasive particle of item 1, wherein the plurality ofabrasive particles are arranged on the surface of the body in acontrolled distribution.

Item 25. The abrasive particle of item 24, wherein the controlleddistribution includes a pattern defined by a plurality of repeatingunits, wherein each repeating unit of the plurality of repeating unitsis substantially the same with respect to each other.

Item 26. The abrasive particle of item 1, wherein a portion of theabrasive particles of the plurality of abrasive particles include acoating comprising a material selected from the group of inorganic,organic, amorphous, crystalline, polycrystalline, ceramic, metal, resin,epoxy, polymer, oxides, carbide, nitride, borides, or a combinationthereof.

Item 27. The abrasive particle of item 1, wherein the surface of thebody including the plurality of abrasive particle comprises a randomarrangement of the plurality of abrasive particles on a major surface ofthe body, and wherein a side surface of the body is essentially free ofthe plurality of abrasive particles.

Item 28. The abrasive particle of item 1, wherein the body comprises afirst major surface and a second major surface separated from the firstmajor surface by a side surface, wherein the plurality of abrasiveparticles are attached to at least the first major surface or the secondmajor surface and the side surface is essentially free of the pluralityof abrasive particles.

Item 29. The abrasive particle of item 1, wherein the body comprises afirst major surface and a second major surface separated from the firstmajor surface by a side surface, wherein the plurality of abrasiveparticles are attached to the first major surface and the second majorsurface and the side surface is essentially free of the plurality ofabrasive particles.

Item 30. The abrasive particle of item 1, wherein the abrasive particleis incorporated into a fixed abrasive article.

Item 31. The abrasive particle of item 1, further comprising a coatedabrasive article including a substrate and the abrasive particleoverlying the substrate, wherein the abrasive particle has apredetermined orientation on the coated abrasive defined by anorientation of the at least one surface including the plurality ofabrasive particles relative to a longitudinal or lateral axis of thesubstrate.

Item 32. The abrasive particle of item 1, further comprising a bondedabrasive article including a body including a bond matrix material,wherein the abrasive particle has a predetermined position andorientation within the body defined by a predetermined position andorientation of the at least one surface including the plurality ofabrasive particles relative to a longitudinal or lateral axis of thebody.

Item 33. An abrasive article comprising: a bond material; and a firstcollection of abrasive particles coupled to the bond material, whereineach particle in the first collection comprises: a shaped abrasiveparticle comprising a body; and a plurality of abrasive particles bondedto at least one surface of the body of the shape abrasive particle.

Item 34. A method of forming an abrasive particle comprising forming amixture and attaching a plurality of abrasive particles to at least onesurface of the mixture and forming a shaped abrasive particle having abody and the plurality of abrasive particles bonded to at least onesurface of the body.

Item 35. The method of item 34, wherein forming a mixture includes atleast one process selected from the group consisting of printing,molding, casting, cutting, ablating, punching, drying, cracking,sintering, humidifying, and a combination thereof.

Item 36. The method of item 34, wherein forming the mixture includesforming a precursor shaped abrasive particle and attaching a pluralityof abrasive particles to at least one surface of the precursor shapedabrasive particle.

Item 37. The method of item 34, wherein forming the mixture includesdepositing the mixture into an opening of a production tool andattaching a plurality of abrasive particles to at least one surface ofthe mixture in the opening of the production tool.

Item 38. The method of item 34, wherein the plurality of abrasiveparticles is attached the body of the mixture prior to substantialdrying of the body.

Item 39. The method of item 34, wherein attaching the plurality ofabrasive particles includes depositing the plurality of abrasiveparticles on a surface of the body, wherein depositing includes aprocess selected from the group consisting of blasting, projecting,pressing, gravity coating, molding, stamping, and a combination thereof.

Item 40. The method of item 34, wherein the mixture is formed on aproduction tool including a layer of abrasive particles including theplurality of abrasive particles.

Item 41. The method of item 34, wherein the process further comprisingapplying moisture to at least one surface of the mixture prior toattaching the plurality of abrasive particles.

Item 42. The method item 34, wherein attaching the plurality of abrasiveparticles includes directing a deposition material at the at least onesurface, wherein the deposition material includes the plurality ofabrasive particles and a carrier gas.

Item 43. The method item 42, wherein the carrier gas can include watervapor, steam, an inert gas element, and a combination thereof.

Item 44. The method item 34, wherein the mixture is formed on aproduction tool including a layer of abrasive particles including theplurality of abrasive particles.

Item 45. The method item 34, wherein the process further comprisingapplying moisture to at least one surface of the mixture prior toattaching the plurality of abrasive particles.

Item 46. The method item 45, wherein applying moisture includesdirecting a gas towards the at least one surface of the mixture prior toattaching the plurality of abrasive particles.

Item 47. The method item 45, wherein applying moisture includesdirecting steam at the at least one surface of the mixture in theproduction tool.

Item 48. The method item 45, wherein applying moisture includes wettingthe at least one surface of the mixture for a sufficient time to changea viscosity of an exterior region of the at least one surface relativeto a viscosity of the mixture at an interior region spaced apart fromthe exterior region.

Item 49. The method item 34, wherein the process further compriseschanging a viscosity of an exterior region of the body including the atleast one surface relative to a viscosity of an interior region of themixture that is spaced apart from the exterior region, and applying theplurality of abrasive particles to the exterior region of the mixture.

EXAMPLES Example 1

Three samples of shaped abrasive particles were made and tested forcomparison of performance. A first comparative sample (CS1) was aconventional shaped abrasive particle commercially available as 3M984Ffrom 3M Corporation. The body had an average width of 1400 microns and aheight of approximately 300 microns. The shaped abrasive particles ofSample CS1 had a rare-earth element doped alpha-alumina composition, anaverage tip sharpness of approximately 20 microns, an average strengthof approximately 606 MPa and an average cross-sectional shape factor ofapproximately 0.15. FIG. 14 includes an image of a shaped abrasiveparticle from Sample CS1.

Two samples (Sample S1 and Sample S2) representative of the embodimentsherein were formed from a gel mixture including approximately 45-50 wt %boehmite. The boehmite was obtained from Sasol Corp. as Catapal B andmodified by autoclaving a 30% by weight mixture of the Catapal B withdeionized water and nitric acid. The nitric acid-to-boehmite ratio wasapproximately 0.025. The mixture was then placed in an autoclave andtreated at 100° C. to 250° C. for a time ranging from 5 minutes to 24hours. The autoclaved Catapal B sol was dried by conventional means. Onemay also use an alternative boehmite, commercially available as DISPERALfrom Sasol Corp. The boehmite was mixed and seeded with 1% alpha aluminaseeds relative to the total alumina content of the mixture. The alphaalumina seeds were made by milling of corundum using conventionaltechniques, described for example in U.S. Pat. No. 4,623,364. Themixture also included 45-50 wt % water and 2.5-4 wt % additional nitricacid, which were used to form the gel mixture. The ingredients weremixed in a planetary mixer of conventional design and mixed underreduced pressure to remove gaseous elements from the mixture (e.g.,bubbles).

Sample S1 was formed by hand by depositing the gel into the openings ofa stainless steel production tool. The cavities were open to both sidesof the production tool, such that they were apertures extending throughthe entire thickness of the production tool. The cavities or openings ofthe production tool had an equilateral triangle two-dimensional shape asviewed top down, wherein the length was approximately 2.77 mm, the widthwas approximately 2.4 mm and the depth was approximately 0.59 mm. Thesurfaces of the openings in the production tool were coated with alubricant of olive oil to facilitate removal of the precursor shapedabrasive particles from the production tool.

After depositing the gel, a first side of the mixture was humidifiedwith a sponge while residing in the cavities of the production tool. Aplurality of dried, unsintered particles of the same gel mixture used toform the mixture in the production tool were deposited on the humidifiedsurface of the mixture residing in the cavities of the production tool.The plurality of unsintered particles were sieved using a 100 US mesh(ASTM E-11 with openings of 150 microns), such that the maximum particlesize of the plurality of unsintered particles was less than 100 US mesh.The plurality of abrasive particles had an absorbed moisture content ofapproximately 10-15% for the total weight of the particles.

The production tool was then inverted and the opposite side of the gelmixture was humidified with a sponge while residing in the cavities ofthe production tool. The plurality of abrasive particles were thenapplied to the humidified surface, such that both major surfaces of theexposed gel mixture in the cavities of the production tool were coatedwith a plurality of abrasive particles. The excess abrasive particleswere removed and the mixture and plurality of abrasive particles weredried in the cavities at approximately 50° C. for 10 minutes using IRlamps and a fan to form precursor abrasive particles. The precursorabrasive particles were removed from the production tool and sintered atapproximately 1325° C. for approximately 10 minutes to achieve at least98% theoretical density. The resulting abrasive particles had a bodyincluding a triangular two-dimensional shape including a length ofapproximately 1550 microns, a width of approximately 1350 microns, and aheight of approximately 300 microns. FIGS. 11A and 11B includecross-sectional images of a representative abrasive particle of SampleS1. The abrasive particle of Sample S1 had an average strength ofapproximately 847 MPa, an average tip sharpness of 20 microns, a ShapeIndex of approximately 0.5, and an average cross-sectional shape factorof approximately 29%.

Sample S2 was formed using the same gel mixture as noted above forSample S1. The gel mixture was placed in a die and extruded intoopenings of a production tool made of PEEK that was translated under thedie as described in embodiments herein. The openings in the productiontool were the same as described above for the production tool used inSample S1, except that the production tool had a thickness ofapproximately 0.54 mm. In a first batch of Sample S2 (Sample BatchS2B1), a plurality of abrasive particles were deposited via gravity on asingle side of the gel mixture while it resided in the cavities of theproduction tool. The plurality of abrasive particles was the same asused in Sample S1. FIG. 15 includes a top-down view and a side view of arepresentative abrasive particle of Sample Batch S2B1.

In a second batch of Sample S2 (Sample Batch S2B2), a plurality ofabrasive particles was deposited on both major surfaces of the mixturewhile it resided in the cavities of the production tool. For a firstmajor surface, the plurality of abrasive particles was deposited viagravity (e.g., by sprinkling the particles on the production tool andgel mixture in the cavities). For the opposite major surface, theplurality of abrasive particles was contained on a surface that isrepeatedly pressed against the bottom surface of the production tool toapply the abrasive particles to the bottom surface of the gel mixturewhile it resided in the cavities. Thus, a plurality of abrasiveparticles was applied to both major surfaces of the gel mixture while itresided in the cavities. The plurality of abrasive particles was thesame as described in Sample S1. FIG. 16 includes a top-down image and aside view image of an abrasive particle of Sample Batch S2B2.

In both batches of Sample S2, the production tool was translated througha set of rollers that applied pressure to the top and bottom surfaces ofthe production tool and assisted with imbedding the abrasive particlesinto the gel mixture while it resided in the cavities.

For both batches of Sample S2, the mixture was dried for approximately 5minutes at approximately 50-55° C. using an IR lamp and a fan. For bothbatches of Sample S2, the samples were removed from the production tooland sintered according to the conditions as provided in Sample S1. Theabrasive particles of Sample Batch S1B1 had an average tip sharpness of20 microns, a Shape Index of approximately 0.5, and an averagecross-sectional shape factor of approximately 21%. The abrasiveparticles of Sample Batch S1B2 had an average tip sharpness of 20microns, a Shape Index of approximately 0.5, and an averagecross-sectional shape factor of approximately 30%.

Samples CS1 and S1 were tested according to a single grit grinding test(SGGT) in a major surface orientation and side orientation. Inconducting the SGGT, one single shaped abrasive particle is held in agrit holder by a bonding material of epoxy. The shaped abrasive particleis secured in the desired orientation (i.e., major surface orientationor side surface orientation) and moved across a workpiece of 304stainless steel for a scratch length of 8 inches using a wheel speed of22 m/s and an initial scratch depth of 30 microns. The shaped abrasiveparticle produces a groove in the workpiece having a cross-sectionalarea (AR). For each sample set, each shaped abrasive particle completes15 passes across the 8 inch length, 10 individual particles are testedfor each of the orientation and the results are analyzed. The testmeasures the tangential force exerted by the grit on the workpiece, inthe direction that is parallel to the surface of the workpiece and thedirection of the groove, and the net change in the cross-sectional areaof the groove from beginning to the end of the scratch length ismeasured to determine the shaped abrasive particle wear. The net changein the cross-sectional area of the groove for each pass can be measured.For the SGGT, the net cross-sectional area of the groove is defined asthe difference between the cross-sectional area of the groove below thesurface and the cross sectional area of the material displaced above thesurface. Performance (Ft/A) is defined as the ratio of the tangentialforce to the net cross-sectional area of the groove.

The SGGT is conducted using two different orientations of the shapedabrasive particles relative to the workpiece. The SGGT is conducted witha first sample set of shaped abrasive particles in a major surfaceorientation wherein a major surface of each shaped abrasive particle isoriented perpendicular to the grinding direction such that the majorsurface initiates grinding on the workpiece. The results of the SGGTusing the sample set of shaped abrasive particles in a major surfaceorientation allows for measurement of the grinding efficiency of theshaped abrasive particles in a major surface orientation.

The SGGT is also conducted with a second sample set of shaped abrasiveparticles in a side surface orientation wherein a side surface of eachshaped abrasive particle is oriented perpendicular to the grindingdirection such that the side surface initiates grinding of theworkpiece. The results of the SGGT test using the sample set of shapedabrasive particles in a side orientation allows for measurement of thegrinding efficiency of the shaped abrasive particles in a sideorientation.

FIG. 17 includes a plot of force per total area removed from theworkpiece for a front orientation (left hand bar) and side orientation(bar on the right) for Sample CS1 and Sample S1. The force per totalarea removed is a measure of the grinding efficiency of the shapedabrasive particles, with a lower force per total area removed indicatingmore efficient grinding performance. As illustrated, Sample S1demonstrated an essentially equivalent performance compared to SampleCS1. This result is quite remarkable considering those of skill in theart have previously disclosed that the most efficient cutting action ofabrasive particles is likely to a result from particles having a highshape fidelity marked by sharp edges and smooth surfaces (i.e., like achisel). See, for example, U.S. Pat. Nos. 4,261,706, 5,603,738 and USPat. Publ. 20100319269. However, the abrasive particles of theembodiments herein have demonstrated notable performance differenceswhen compared to conventional abrasive particles in light of the noteddifferences between the abrasive particles and conventional abrasiveparticles having relatively smooth sides and sharp edges. Notably, theabrasive particles herein have surfaces that are characterized byirregular contours including randomly arranged protrusions and valleyson one or more surfaces of the shaped abrasive particles, which is incontrast to the teachings of the prior art that suggest one should makethe surfaces of a shaped abrasive particle smooth and the edges sharpfor the best performance.

Abrasive particles Sample Batch S2B1 were formed into coated abrasivearticles having the construction, which is provided below. A backing offinished cloth of 18 pounds per ream were obtained and coated with amake formulation including of a phenol formaldehyde as provided inTable 1. The web with the make coat was then followed by anelectrostatic deposition process applying 40 pounds per ream of abrasiveparticles from Sample Batch S2B1. This partial structure of make coatedweb and grain was then dried in an oven for two hours at 80° C.

TABLE 1 Make Formulation Make Formulation Component Vendor PercentageFiller NYAD Wollast 325 NYCO  34% Wet Witcona 1260 Witco 0.10% Resin,Single Comp 94-908 Durez  57% Nalco 2341 Defoamer Nalco 0.10% PET-3MP(PTM) Bruno Bloc 5.70% Water — 3.10%

The coated abrasive structures were then coated with 14 pounds per reamof a phenol formaldehyde size coat. The detailed composition of the sizecoat is presented in Table 2. The web was transported through a drierwhich had a dry bulb temperature setting of 120° C. for a period of twohours.

TABLE 2 Size Formulation Size Formulation Component Vendor PercentageWhite Dye E-8046 Acrochem Corp 0.70% Wet Witcona 1260 Witco 0.20% SolmodTamol 165A Rohm & Haas 0.90% Filler Syn Cryolite Solvay 42.40% ResinSingle Comp 94-908 Durez 48.30% Nalco 2341 Defoamer Nalco 0.10% PET-3MPPolythiol (PTM) Bruno Bloc 2.50% Dye Unisperse Black Ciba 0.20% Water —4.80%

The coated abrasive sample was then placed into a convection oven toundergo a post curing step in which the oven temperature was 125° C. for12 hours.

A third sample of a coated abrasive, Sample S3 was also made. Theabrasive particles of Sample S3 were made according to the process usedto make the abrasive particles of Sample Batch S2B1, but did not includedeposition of a plurality of abrasive particles on the shaped abrasiveparticles. The construction of the coated abrasive of Sample S3 was thesame as for the coated abrasive including the particles of Sample BatchS2B1. Particles of Sample CS1 were tested as a conventional coatedabrasive article commercially available at 984F from 3M Corporation.

Each of the three different coated abrasive samples was tested accordingto the conditions summarized in Table 3. Notably, 2 sample coatedabrasives were tested in each case to derive the results.

TABLE 3 Test conditions: Test mode: Dry, straight plunge Constant MRR′ =4 inch³/min/inch Belt speed (Vs) = 7500 sfpm (38 m/s) Work material: 304ss Hardness: 96-104 HRB Size: 0.5 × 0.5 × 12 inches Contact width: 0.5in Contact Wheel: Steel Measurements: Power, Grinding Forces, MRR′ andSGE Cum MR compared at SGE = 2.4 Hp · min/inch³

FIG. 18 includes a plot of specific grinding energy versus cumulativematerial removed (at a material removal rate of 4 inch³/min inch) foreach of the samples. It is notable that the coated abrasive utilizingthe abrasive particles of the Sample Batch S2B1 performed better thanthe coated abrasive including the abrasive particles of Sample S3 andwas essentially equivalent in performance to the coated abrasive sampleincluding the abrasive particles of Sample CS1.

Example 2

A new sample of abrasive particles (Sample S4) was formed. The shapedabrasive particles of Sample S4 were formed from a gel mixture includingapproximately 45-50 wt % boehmite. The boehmite was obtained from SasolCorp. as Catapal B and modified by autoclaving a 30% by weight mixtureof the Catapal B with deionized water and nitric acid. The nitricacid-to-boehmite ratio was approximately 0.025 in the autoclave andtreated at 100° C. to 250° C. for a time ranging from 5 minutes to 24hours. The autoclaved Catapal B sol was dried by conventional means. Theboehmite was mixed and seeded with 1% alpha alumina seeds relative tothe total alumina content of the mixture. The alpha alumina seeds weremade by milling of corundum using conventional techniques, described forexample in U.S. Pat. No. 4,623,364. The mixture also included 45-50 wt %water and 2.5-4 wt % additional nitric acid, which were used to form thegel mixture. The ingredients were mixed in a planetary mixer ofconventional design and mixed under reduced pressure to remove gaseouselements from the mixture (e.g., bubbles).

The gel was then placed in a die and extruded into openings of aproduction tool translated under the die at a suitable speed relative tothe deposition rate such that the openings were sufficiently filled. Thecavities were open to both sides of the production tool, such that theywere apertures extending through the entire thickness of the productiontool. The cavities or openings of the production tool had an equilateraltriangle two-dimensional shape as viewed top down, wherein the lengthwas approximately 2.77 mm, the width was approximately 2.4 mm and thedepth was approximately 0.60 mm. The production tool had a thickness ofapproximately 0.60 mm. The surfaces of the openings in the productiontool were coated with a lubricant of canola oil to facilitate removal ofthe precursor shaped abrasive particles from the production tool.

After depositing of the gel into the openings of the production tool, aplurality of dried, unsintered, particles of the same gel materialdeposited in the openings were projected at the surface of the gel inthe production tool. The plurality of abrasive particles were forciblyejected toward the gel in the production tool using air as the carriermaterial at an approximate pressure of 40 psi. The process of applyingthe plurality of abrasive particles was completed in a container,wherein a vast majority of the excess or unbonded abrasive particlescould be captured and recycled for future application processes. The gelwas not humidified prior to deposition of the plurality of abrasiveparticles. Prior to deposition, the plurality of dried, unsinteredparticles were sieved using a 100 US mesh (ASTM E-11 with openings of150 microns), such that the maximum particle size of the plurality ofunsintered particles was less than 100 US mesh. The plurality ofabrasive particles had an absorbed moisture content of approximately10-15% for the total weight of the particles. Approximately 70% of theprecursory shaped abrasive particle had a suitably high coverage of theplurality of dried, unsintered particles on the first major surface.

The excess dried, unsintered particles were removed and the mixture andplurality of abrasive particles were dried in the cavities atapproximately 50° C. for 30 seconds using IR lamps and a fan to formprecursor abrasive particles. The precursor abrasive particles wereremoved from the production tool, pre-sintered at 800° C. and sinteredat approximately 1320° C. for approximately 15 minutes to achieve 98%theoretical density. The resulting abrasive particles had a bodyincluding a triangular two-dimensional shape including a length ofapproximately 1550 microns, a width of approximately 1350 microns, and aheight of approximately 300 microns. The abrasive particle of Sample S4had an average strength of approximately 20.3 MPa, an average tipsharpness of 30 microns, a Shape Index of approximately 0.5.

Another sample of abrasive particles (Sample CS4) were formed in thesame manner as noted above for Sample S4, except that the abrasiveparticles did not include a plurality of abrasive particles on thesurface of the shaped abrasive particles (i.e., unmodified shapedabrasive particles).

Two samples of coated abrasive articles were formed from the abrasiveparticles of Samples S4 and CS4 to create coated abrasive samples CAS4and CACS4, respectively. The coated abrasive samples CAS4 and CACS4 wereformed in the same manner used to form the coated abrasive samples ofExample 1 for Samples CS1 and Sample Batch S2B1.

Each coated abrasive sample was tested according to the test outlined inTable 4 below. Two samples of the coated abrasives were tested in eachcase to derive the results.

TABLE 4 Test Conditions Test mode Dry, constant depth of cut (rise/fall)Constant MRR′ = 2.3 inch³/min/inch Belt Speed (Vs) = 7500 sfpm (38 m/s)Work Material: 1045 Carbon Steel Hardness: 85-95 HRB Size: 1 × 0.25inches Contact width: o.25 inches Contact wheel for belt: Steel wheelMeasurements: Power, MRR′ and SGE Cum. MR compared at SGE = 3.2 Hpmin/inch³

FIG. 19 includes a plot of specific grinding energy versus cumulativematerial removed from the workpiece. As illustrated, Sample CAS4demonstrates improved cumulative material removed and lower specificgrinding energy, especially near the end of the test, compared to SampleCACS4.

Example 3

Five samples of abrasive particles (S5-1, S5-2, S5-3, S5-4, and S5-5)were formed to investigate the impact of the median particle size of theplurality of abrasive particles on the percent coverage of the abrasiveparticles on at least one surface of the shaped abrasive particles.Table 5 below summarizes the impact of the median particle size of theplurality of abrasive particles on the percent coverage of the pluralityof abrasive particles on a first major surface of a shaped abrasiveparticle having a generally triangular two-dimensional shape having alength of approximate 1550 μm, a width of approximately 1350 μm, and aheight of approximately 320 μm. The abrasive particles were formed inthe same manner used to form Sample S4 of Example 2, except that thesurfaces of the gel in the production tool were humidified prior todeposition of the plurality of dried, unsintered abrasive particles. Thehumidification process utilized steam (i.e. a mix of water in thegaseous state and suspended liquid particles) directed at the surfacesof the gel in the production tool.

TABLE 5 Percentage of D50 of dried particles in the batch Sample IDunsintered grains having covered S5-1 125-89 μm  24% S5-2 89-64 μm 38%S5-3 64-45 μm 95% S5-4 45-38 μm 96% S5-5 76-45 μm 96%

FIGS. 20A-20E include images of the abrasive particles of Samples S5-1,S5-2, S5-3, S5-4, and S5-5, respectively. Notably, the median particlesize of the plurality of abrasive particles relative to the size of theshaped abrasive particle had an impact on the percent coverage of theplurality of abrasive particles on the surface of the shaped abrasiveparticles.

Example 6

Four samples of abrasive particles (Sample S6-1, Sample S6-2, CS1, andSample S6-3) were tested according to the single grit grinding test, asdescribed in Example 1. Sample S6-1, Sample 56-2, and Sample S6-3 wereformed in the same manner as Sample S4 of Example 2, except that SampleS6-1 had an average of 32 abrasive particles bonded to the majorsurfaces of the bodies of the shaped abrasive particles and Sample S6-2had an average of 7 abrasive particles bonded to the major surfaces ofthe bodies of the shaped abrasive particles. Sample S6-3 had noplurality of abrasive particles bonded to the surface of the shapedabrasive particle.

FIG. 21 includes a plot of force per total area removed from theworkpiece for a front orientation (left hand bar) and side orientation(bar on the right) for Sample S6-1, S6-2, S6-3, and CS1 (same asprovided in Example 1). Surprisingly, Sample S6-2 demonstrated a greatervariation in the cutting efficiency in the front orientation compared toSample S6-1. Sample S6-1 also demonstrated a lower variation in thecutting efficiency compared to Sample S6-3 and CS1 in the frontorientation.

Example 7

Two samples of abrasive particles were made. A first sample, Sample S7-1was formed in the same manner used to form Sample S4 of Example 2 exceptthat the surfaces of the gel in the production tool were humidifiedprior to deposition of the plurality of dried, unsintered abrasiveparticles. The humidification process utilized steam directed at thesurfaces of the gel in the production tool. The plurality of abrasiveparticles attached to the first major surface of the shaped abrasiveparticle of Sample S7-1 had not been calcined or sintered. A secondsample, Sample S7-2 was formed in the same manner used to form SampleS7-1, except that sintered alpha alumina grains were used for theplurality of abrasive particles attached to a first major surface of theshaped abrasive particles. Sample S7-1 demonstrated significantly bettercoverage, wherein 90-95% of the particles were suitably covered with theplurality of abrasive particles compared to Sample S7-2, which had only60-70% of total particles formed with a suitable covering of theplurality of abrasive particles for the first major surface of theshaped abrasive particles. It is theorized that the sintered abrasiveparticles applied to the surface of the precursor shaped abrasiveparticles for Sample S7-2 did not bond well to the surface, but thegreen, unsintered grains applied to the surface of Sample S7-1 hadimproved bonding as the dried grains could re-gel with the humidifiedsurface of the gel prior to further processing.

Example 8

Two samples of abrasive particles were made. A first sample, Sample S8-1was formed in the same manner used to form Sample S4 of Example 2. Theplurality of abrasive particles attached to the first major surface ofthe shaped abrasive particle of Sample S8-1 had not been calcined orsintered. A second sample, Sample S8-2 was formed in the same mannerused to form Sample S8-1, except that no abrasive particles weredeposited on the surfaces of the gel or resulting shaped abrasiveparticles.

Coated abrasive articles in the form of discs having a diameter of 7inches were then created using the abrasive particles of Samples S8-1and S8-2 to create samples CAS8-1 and CAS8-2, respectively. The samplesCAS8-1 and CAS8-2 were formed according to the following process:

A make coat formulation as provided in Table 6 below was applied to afiber backing material available from Sachsenroder having an averagethickness of 0.95 mm. The wet laydown weight of the make coat was 9lbs/ream +/−0.3 lbs and was applied using a two roll coat method using asteel roll over a 65-72 Shore A durometer hard rubber roll.

TABLE 6 Component % based on Weight Phenolic Resin (SI 48.25 HRJ15993)Solmod Silane A1100 0.44 Wet Witconate 1260 0.15 Filler NYADWollastonite 48.25 400 Water 2.91

The viscosity of the formulation was adjusted using water to a range of9500 to 10500 cps at 100° F. After the make coat was applied, theabrasive particles of Samples S8-1 and S8-2 were silane treated andapplied to the make coat via electrostatic projection. The target grainweight for each of the samples was 55 lbs/ream +/−3 lbs. The particlesof each of the samples were pre-heated before projection.

After projecting the particles onto the make coat and backing, the makecoat was cured in a festoon oven using the following process: step 1) 42minutes at 150° F.; step 2) 42 minutes at 170° F.; step 3) 38 minutes at200° F.; step 4) 43 minutes at 215° F.; and step 5) 23 minutes at 230°F.

After the make coat was cured, a size coat having the formulationprovided in Table 7 was applied to the surface of the particles andcured make coat.

TABLE 7 Component % based on Weight Phenolic Resin (SI 53.04 HRJ15993)Solmod Tamol 165A 0.84 Air Prod DF70 Defoamer 0.12 Black Pigment 2.41Filler Syn Cryolite K 42.43 Water 1.16

The formulation of the size coat was adjusted using water to a viscosityrange of 5400 to 5600 cps at 100° F. The size coat was applied using thesame machine set up as used to apply the make coat. The size iscontrolled visually versus a known standard including a gap setting forthe two roll coater was set at 0.045 inches.

After applying the size coat, the material was cured in a festoon ovenusing the following process: step 1) 20 minutes at 130° F. and 45% RH;step 2) 20 minutes at 170° F.; step 3) 20 minutes at 190° F.; step 4) 20minutes at 210° F.; and step 5) 30 minutes at 235° F. The material isthen rolled up and cured in a post cure oven for 12 hours at 250° F.

Upon removing the roll from the post cure oven the backing is flexed andre-moisturized by application of water.

Each of the coated abrasive samples were tested according to theconditions summarized below in Table 8.

TABLE 8 Test mode dry, constant force of rotating disc in a linearlytraveling workpiece Constant Force 8 lb Disc speed 6000 rpm Medium hardbackup pad (e.g., rubber) Work piece linear speed 15 fpm Angle betweendisc and work piece is 10 degrees Work material A36 hot rolled steelContact width  1/8 inch Grind time 1 minute intervals Measurements Gramscut per 1 minute interval Grams lost from disc per 1 minute interval Endpoint: less than 2 g material removed in the interval

FIG. 22 includes a plot of relative performance (% cut) for SamplesCAS8-1 and CAS8-2 relative to a conventional coated abrasive sample,Sample CACS8-3, available as 982C from 3M Corporation. As illustrated,Sample CAS8-1 had essentially the same performance compared to theconventional coated abrasive sample. By contrast, Sample CAS8-2demonstrated a relative performance of approximately 20% less comparedto the conventional sample the Sample CAS8-1.

All values, ratios, percentages and/or quantified data provided hereinwith respect to an abrasive particle of any embodiment, can also be anaverage derived from a random and statistically relevant sample size ofrepresentative abrasive particles. For example, with respect to thepercent coverage of the plurality of abrasive particles on the body,such percentages can also be calculated from a random and statisticallyrelevant sample size of a batch of abrasive particles. The size of thesample may differ depending upon the size of the batch.

Notably, reference herein to a composition that is “free of” anothermaterial (e.g., material Z) may be interpreted as a composition that mayhave traces or impurity contents of material Z, but such contents do notmaterially affect the properties of the composition. For example, amaterial may be “free of” a particular species and such species may bepresent in an amount of not greater than 0.1% or not greater than 0.01%or not greater than 0.001%. This paragraph is not to be interpreted tonarrow any other disclosure in the foregoing embodiments and is intendedonly to define those instances using the term “free of.” Moreover, ininstances where a particular species is not expressly identified,Applicants reserve the right to further define the material as beingfree of said particular species. However, unless the terminology “freeof” is expressly recited, such a term cannot be interpreted to narrowthose embodiments or claims using inclusive terms, such as “including,”“having,” “comprising,” and the like.

The above-disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true scope of the present invention. Thus, to the maximum extentallowed by law, the scope of the present invention is to be determinedby the broadest permissible interpretation of the following claims andtheir equivalents, and shall not be restricted or limited by theforegoing detailed description.

The Abstract of the Disclosure is provided to comply with Patent Law andis submitted with the understanding that it will not be used tointerpret or limit the scope or meaning of the claims. In addition, inthe foregoing Detailed Description, various features may be groupedtogether or described in a single embodiment for the purpose ofstreamlining the disclosure. This disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter may be directed toless than all features of any of the disclosed embodiments. Thus, thefollowing claims are incorporated into the Detailed Description, witheach claim standing on its own as defining separately claimed subjectmatter.

What is claimed is:
 1. An abrasive particle comprising: a bodycomprising a length defined by a longitudinal axis, a width defined by alateral axis and a height defined by a vertical axis; wherein the bodyhas a primary aspect ratio of length:width of at least 1.1:1; and aplurality of abrasive particles coupled to at least one surface of thebody of the abrasive particle.
 2. The abrasive particle of claim 1,wherein the abrasive particle is a shaped abrasive particle.
 3. Theabrasive particle of claim 2, wherein the body has a first end surface,a second end surface and a side surface extending between the first endsurface and the second end surface.
 4. The abrasive particle of claim 3,wherein the first end surface or the second end surface of the bodycomprises a two-dimensional shape as viewed in a plane defined by aheight and a width of the body selected from the first group consistingof regular polygons, irregular polygons, ellipsoids, numerals, Greekalphabet characters, Latin alphabet characters, Russian alphabetcharacters, complex shapes having a combination of polygonal shapes, ashape with linear and curved portions, and a combination thereof.
 5. Theabrasive particle of claim 3, wherein the plurality of abrasiveparticles is bonded to at least two surfaces of the body.
 6. Theabrasive particle of claim 1, wherein a portion of the plurality ofabrasive particles is embedded within the at least one surface of thebody.
 7. The abrasive particle of claim 1, wherein a portion of theplurality of abrasive particles is bonded directly to the at least onesurface of the body.
 8. The abrasive particle of claim 1, wherein aportion of the abrasive particles of the plurality of abrasive particlesare sinter-bonded to the at least one surface of the body of theabrasive particle and the plurality of abrasive particles are selectedfrom the group consisting of oxides, carbides, nitrides, borides,oxycarbides, oxynitrides, oxyborides, natural minerals, syntheticmaterials, carbon-based materials, and a combination thereof.
 9. Theabrasive particle of claim 3, wherein the first end surface is angledwith respect to the side surface.
 10. The abrasive particle of claim 1,wherein the plurality of abrasive particles comprise a median particlesize (D50), and wherein the median particle size (D50) is at least 0.1%and not greater than about 20% of the length of the body, at least 0.1%and not greater than about 20% of the width of the body, and at least0.1% and not greater than about 20% of the height of the body.
 11. Theabrasive particle of claim 1, wherein the plurality of abrasiveparticles comprise a median particle size (D50) of at 0.1 microns andnot greater than 80 microns.
 12. The abrasive particle of claim 1,wherein the plurality of abrasive particles cover not greater than 95%of a total surface area of the body.
 13. The abrasive particle of claim1, wherein the abrasive particle is incorporated into a fixed abrasivearticle.
 14. The abrasive particle of claim 1, wherein the abrasiveparticle comprises alpha alumina.
 15. The abrasive particle of claim 1,wherein the abrasive particle is extruded.
 16. An abrasive particlecomprising: an extruded, elongated body including a first end surface, asecond end surface, and a side surface extending between the first endsurface and the second end surface; and a plurality of abrasiveparticles coupled to at least one surface of the body.
 17. The abrasiveparticle of claim 16, wherein the plurality of abrasive particles arebonded to at least a portion of the side surface of the body.
 18. Theabrasive particle of claim 17, wherein the plurality of abrasiveparticles is bonded to at least a portion of the surface and at leastthe first end surface or second end surface is essentially free of theplurality of abrasive particles.
 19. The abrasive particle of claim 16,wherein the first end surface or the second end surface of the bodycomprises a two-dimensional shape as viewed in a plane defined by aheight and a width of the body selected from the first group consistingof regular polygons, irregular polygons, ellipsoids, numerals, Greekalphabet characters, Latin alphabet characters, Russian alphabetcharacters, complex shapes having a combination of polygonal shapes, ashape with linear and curved portions, or a combination thereof.
 20. Theabrasive particle of claim 16, wherein the body comprises a materialselected from the group consisting of oxides, carbides, nitrides,borides, oxycarbides, oxynitrides, oxyborides, natural minerals,synthetic materials, carbon-based materials, or a combination thereof,and wherein the plurality of abrasive particles comprise a materialselected from the group consisting of oxides, carbides, nitrides,borides, oxycarbides, oxynitrides, oxyborides, natural minerals,synthetic materials, carbon-based materials, or a combination thereof.